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ma28151 1/22 figure 1: ma28151 block diagram the ma28151 is based on the industry standard 8251a universal synchronous asynchronous receiver/transmitter (usart), modified for data communications with the mas281 microprocessor. the ma28151 is used as a peripheral device and is programmed by the cpu to operate using virtually any serial data transmission technique presently in use (including ibm bi-sync). the usart accepts data characters from the cpu in parallel format and then converts them into a continuous serial data stream for transmission. simultaneously, it can receive serial data streams and convert them into parallel data characters for the cpu. the usart signals the cpu whenever it receives a character for transmission or whenever it receives a character for the cpu. the cpu can read the complete status of the usart at any time, including data transmission errors and control signals such as syndet and txempty. features n radiation hard to 1mrad(si) n latch up free, high seu immunity n silicon-on-sapphire technology n synchronous 5 - 8 bit characters; internal or external character synchronisation; automatic sync insertion n asynchronous 5 - 8 bit characters; clock rate - 1, 16 or 64 times baud rate; break character generation, 1 1 M 2 or 2 stop bits n all inputs and outputs are ttl compatible n compatible with the mas281 (mil-std-1750a) microprocessor the ma28151 is based on the industry standard 8251a usart, modified for use with the mas281 processor, incorporating the following features: 1. ma28151 has double-buffered data paths with separate l/o registers for control status, data in and data out, which considerably simplifies control programming and minimizes cpu overhead. 2. in synchronous operations, the receiver detects and handles break automatically, relieving the cpu of this task. 3. a refined rx initialisation prevents the receiver from starting when in the break state, preventing unwanted interrupts from the disconnected usart. 4. at the conclusion of a transmission, the txd line will always return to the marking state unless sbrk is programmed. 5. tx enable logic enhancement prevents a tx disable command from prematurely halting transmission of the previously written data before completion. the logic also prevents the transmitter from turning off in the middle of a word. 6. when external sync detect is programmed, internal sync detect is disabled and an external sync detect status is provided via a flip-flop, which clears itself upon a status read. 7. the possibility of a false sync detect is minimized in two ways: by ensuring that if double character sync is programmed, the characters will be continuously detected and by clearing the rx register to all 1s whenever enter-hunt command is issued in sync mode. 8. when the ma28151 is not selected, the rdwn and dsn lines do not affect the internal operation of the device. 9. the ma28151 status can be read at any time but the status update will be inhibited during status read. 10. the ma28151 is free from extraneous glitches, providing higher speed and better operating margins. 11. synchronous baud rate is from dc to 64k. 12. asynchronous baud rate is from dc to 19.2k. ma28151 radiation hard programmable communication interface replaces jone 1999 version, ds3574-4.0 ds3574-5.0 january 2000
ma28151 2/22 1. functional description 1.1 general the ma28151 is a universal synchronous/asynchronous receiver/transmitter designed for use with the mas281 microprocessor. like other l/o devices in a microcomputer system, its functional configuration is programmed by the systems software for maximum flexibility. the ma28151 can support most serial data techniques in use, including ibm bi- sync. in a communication environment, an interface device must convert parallel format system data into serial format for transmission, and convert incoming serial data into parallel system data for reception. the interface device must also delete or insert bits or characters that are functionally unique to the communication technique. in essence, the interface should appear transparent to the cpu for the simple input or output of byte-oriented system data. 1.2 data bus buffer this 3-state, bidirectional, 8-bit buffer is used to interface the ma28151 to the system data bus. data is transmitted or received by the buffer upon execution of output or input instructions from the cpu. control word, command words and status information are also transferred through the data bus buffer. the command status, data-in and data-out registers are separate 8-bit registers, communicating with the system bus through the data bus buffer. this functional block accepts inputs from the system control bus and generates control signals for overall device operation. it contains the control word register and command word register, which store the various control formats for the devices functional definition. 1.3 reset a high on this input forces the ma28151 into idle mode. the ma28151 will remain at idle until its functional definition is programmed with a new set of control words. minimum reset pulse width is 6 tcy (clock must be running). the device can also be put into the idle state by a command reset operation . 1.4 clock (clk) the clk input is used to generate internal device timing and is normally connected to the clock generator (osc) of the system. please note: none of the external inputs or outputs are referenced to clk but the frequency of clk must be greater than 30 times the receiver or transmitter data bit rates. 1.5 data strobe (dsn) this input indicates that a data transfer is taking place. during a cpu write operation the ma28151 reads data from the bus on the rising edge of dsn. during a read operation the ma28151 can output data while dsn is low. data is valid on the rising edge of dsn. 1.6 read/write select (rdwn) a high on the rdwn input indicates a read of data or status information from the ma28151. a low on this input indicates a transfer of data or control words into the ma28151. the rdwn line is valid only when dsn is low. figure 2 summarises the mas28151 read/write operati ons. 1.7 control/data (cdn) this input, in conjunction with the dsn and rdwn inputs, informs the ma28151 that the word on the data bus is either a data character, control word or status information. 1 = control/status; 0= data cdn rdwn dsn csn action 0 1 0 0 28151 to cpu 0 0 0 0 cpu to 28151 1 1 0 0 status to cpu 1 0 0 0 cpu to control x x 1 0 bus tristate x x x 1 bus tristate figure 2: read/write control 1.8 chip select (csn) a low on this input selects the ma28151. no reading or writing will occur unless the device is selected. when csn is high, the data bus is in the float state and the dsn and rdwn lines have no effect on the chip. 1.9 modem control the ma28151 has a set of control inputs and outputs which can be used to simplify the interface to almost any modem. the modem control signals are general purpose in nature and can be used for functions other than modem control, if necessary. 1.10 data set ready ( dsr ) the dsr input signal is a general-purpose, 1-bit inverting input port. its condition can be tested by the cpu using a status read operation. the dsr input is normally used to test modem conditions such as data set ready. 1.11 data terminal ready ( dtr ) the dtr output signal is a general purpose, 1-bit inverting output port. it can be set low by programming the appropriate bit in the command instruction word. the dtr output signal is normally used for modem control such as data terminal ready.
ma28151 3/22 1.12 request to send ( rts ) the rts output signal is a general purpose, 1-bit inverting output port. it can be set low by programming the appropriate bit in the command instruction word. the rts output signal is normally used for modem control such as request to send. 1.13 clear to send ( cts ) a low on this input enables the ma28151 to transmit serial data if the tx enable bit in the command byte is set to a high. if either a tx enable off or cts off condition occurs while the tx is in operation, the tx will transmit all the data in the usart, written prior to tx disable command, before shutting down. 1.14 transmitter buffer the transmitter buffer accepts parallel data from the data bus buffer, converts it to a serial bit stream, inserts the appropriate characters or bits (based on the communication technique) and outputs a composite serial stream of data on the txd output pin on the falling edge of txc . the transmitter will begin transmission upon being enabled if cts = 0. the txd line will be held in the marking state immediately upon a master reset, or when tx enable or cts = 1, or the transmitter is empty. 1.15 transmitter control the transmitter control manages all activities associated with the transmission of serial data. it accepts and issues signals both externally and internally to accomplish this function. 1.16 transmitter ready (txrdy) this output signals the cpu that the transmitter is ready to accept a data character. the txrdy output pin can be used as an interrupt to the system since it is masked by txenable; or, for polled operation, the cpu can check txrdy using a status read operation. txrdy is automatically reset by the falling edge of dsn (with rdwn low) when a data character is loaded from the cpu. note that when using the polled operation, the txrdy status bit is not masked by txenable, but will only indicate the empty/full status of the tx data input register. 1.17 transmitter empty (txe) when the ma28151 has no characters to send, the txempty output will go high. it resets upon receiving a character from cpu if the transmitter is enabled. txempty remains high when the transmitter is disabled. txempty can be used to indicate the end of transmission mode, so that the cpu can turn the line around in the half-duplex operational mode. in the synchronous mode, a high on the txempty output indicates that a character has not been loaded and the sync character or characters are about to be or are being automatically transmitted as fillers. txempty does not go low when the sync characters are being shifted out. 1.18 transmitter clock (t x c) the transmitter clock controls the rate at which the character is to be transmitted. in the synchronous transmission mode, the baud rate (1x) is equal to the txc frequency. in asynchronous transmission mode, the baud rate is a fraction of the actual txc frequency. a portion of the mode instruction selects this factor; it can be 1,1/16 or 1/64 the txc . for example: if baud rate equals 110 baud txc equals 110hz in the 1x mode txc equals 1 72khz in the 16x mode txc equals 7.04khz in the 64x mode the falling edge of txc shifts the serial data out of the ma28151. 1.19 receiver buffer the receiver accepts serial data, converts the data to parallel format, checks for bits or characters that are unique to the communications techniques and sends an assembled character to the cpu. serial data is input to the rxd pin and is clocked in on the rising edge of rxc. 1.20 receiver control this functional block manages all receiver-related activities which consist of the following features: the rxd initialisation circuit prevents the ma28151 from mistaking an unused input line for an active low data line in the break condition. before starting to receive serial characters on the rxd line, a valid 1 must first be detected after a chip master reset. once this has been determined, a search for a valid low (start bit) is enabled. this feature is only active in the asynchronous mode and is only done once for each master reset. the false start bit detection circuit prevents false starts as the result of a transient noise spike by first detecting the falling edge and then strobing the nominal center of the start bit (rxd = low). parity error detection sets the corresponding status bit. the framing error status bit is set if the stop bit is absent at the end of the data byte (asynchronous mode). 1.21 rxrdy (receiver ready) this output indicates that the ma28151 contains a character that is ready to be input to the cpu. rxrdy can be connected to the interrupt structure of the cpu or, for polled operation, the cpu can check the condition of rxrdy using a status read operation. rxenable, when off holds rxrdy in the reset condition. for asynchronous mode, to set rxrdy, the receiver must be enabled to sense a start bit and a complete character must be assembled and transferred to the data output register. for synchronous mode, to set rxrdy,
ma28151 4/22 the receiver must be enabled and a character must finish assembly and be transferred to the data output register failure to read the received character from the rx data output register prior to the assembly of the next rx data character will set overrun condition error and the previous character will be written over and lost. if the rx data is being read by the cpu when the internal transfer is occurring, the overrun error will be set and the old character will be iost. 1.22 r x c (receiver clock) the receiver clock controls the rate at which the character is to be received. in synchronous mode the baud rate (1x) is equal to the actual frequency of rxc . in asynchronous mode, the baud rate is a fraction of the actual rxc frequency. a portion of the mode instruction selects this factor: 1, 1 M 16 or 1 M 64 of the receiver clock. for example: baud rate equals 300 baud, if rxc equals 300 hz in the 1 x mode: rxc equals 4800 hz in the 16x mode rxc equals 19.2 khz in the 64x mode. baud rate equals 2400 baud if rxc equals 2400hz in the 1x mode rxc equals 38.4 khz in the 16x mode; rxc equals 153.6 khz in the 64x mode. data is sampled into the ma28151 on the rising edge of rxc . note: in most communications systems, the ma28151 will be handling both the transmission and reception operations of a single link. consequently the receive and transmit baud rates will be the same. both txc and rxc will require identical frequencies for this operation and can be tied together and connected to a single frequency source (baud rate generator) to simplify the interface. 1.23 sync/break detect (syndet/brkdet) this pin is used in synchronous mode for syndet and may be used as either input or output, programmable through the control word. it is reset to output mode, low upon reset. when used as an output (internal sync mode), the syndet pin will go high to indicate that the ma28151 has located the sync character in the receive mode. if the ma28151 is programmed to use double sync characters (bi-sync), the syndet will go high in the middle of the last bit of the second sync character. syndet is automatically reset upon a status read operation. when used as an input (external sync detect mode), a positive going signal will cause the ma28151 to start assembling data characters on the rising edge of the next rxc . once in sync, the high input signal can be removed. when external sync detect is programmed, internal sync detect is disabled. 1.24 break (async mode only) this output will go high whenever the receiver remains low through two consecutive stop bit sequences including the start bits, data bits, and parity bits. break detect may also be read as a status bit. it is reset only upon a master chip reset or rx data returning to a one state. c/d action 1 mode instruction 1 sync character 1 (sync only) * 1 sync character 2 (sync only) * 1 command instruction 0 data 1 command instruction 0 data 1 command instruction note: the second sync character is skipped if mode instruction has programmed the ma28151 to single character mode. both sync characters are skipped if mode instruction has programmed the ma28151 to async mode figure 3: typical data block 2. operation description 2.1 general the complete functional definition of the ma28151 is programmed by the systems software. a set of control words must be sent out by the cpu to initialize the ma28151 to support the desired communications format. these control words will program the: baud rate, character length, number of stop bits, synchronous or asynchronous operation, even/ odd/off parity, etc. in the synchronous mode, options are also provided to select either internal or external character synchronization. once programmed, the ma28151 is ready to perform its communication functions. the txrdy output is raised high to signal the cpu that the ma28151 is ready to receive a data character from the cpu. this output (txrdy) is reset automatically when the cpu writes a character into the ma28151. alternatively, the ma28151 receives serial data from the modem or l/o device. upon receiving an entire character, the rxrdy output is raised high to signal the cpu that the ma28151 has a complete character ready for the cpu to fetch. rxrdy is reset automatically upon the cpu data read operation. the ma28151 cannot begin transmission until the txenable (transmitter enable) bit is set in the command instruction and it has received a clear to send ( cts ) input. the txd output will be held in the marking state upon reset.
ma28151 5/22 3. programming the ma28151 3.1 mode and command instructions prior to starting data transmission or reception, the ma28151 must be loaded with a set of control words generated by the cpu. these control signals define the complete functional definition of the ma28151 and must immediately follow a reset operation (internal or external). the control words are split into two formats: 1. mode instruction 2. command instruction 3.1.1 mode instruction this instruction defines the general operational characteristics of the ma28151. it must follow a reset operation (internal or external). once the mode instruction has been written into the ma28151 by the cpu, sync characters or command instructions may be written. 3.1.2 command instruction this instruction defines a word that is used to control the actual operation of the ma28151. both the mode and command instruction must conform to a specified sequence for proper device operation. the mode instruction must be written immediately following a reset operation, prior to using the ma28151 for data communications. all control words written into the ma28151 after the mode instruction will load the command instruction. command instructions can be written into the ma28151 at any time in the data block during the operation of the ma28151. to return to the mode instruction format, the master reset bit in the command instruction word can be set to initiate an internal reset operation. this automatically places the ma28151 back into the mode instruction format. command instructions must follow the mode instructions or sync characters. 3.2 mode instruction definition the ma28151 can be used for either asynchronous or synchronous data communications. to understand how the mode instruction defines the functional operation of the ma28151, the designer can best view the device as two separate components, one asynchronous and the other synchronous, sharing the same package. the format definition can be changed only after a master chip reset. for explanation purposes the two formats will be isolated. note: when parity is enabled it is not considered as one of the data bits for the purpose of programming the word length. the actual parity bit received on the rx data line cannot be read on the data bus. in the case of a programmed character length of less than 8 bits, the least significant data bus bits will hold the data; unused bits are dont care when writing data to the ma28151, and will be zeros when reading the data from the ma28151. 3.3 test mode the mode instruction can be used to select a scan path test facility. in this mode a test vector is read in through rxd and read out in txd. for further information of test mode please contact gec plessey semiconductors. 3.4 asynchronous mode (transmission) whenever a data character is sent by the cpu the ma28151 automatically adds a start bit (low level), followed by the data bits (least significant bit first,) and the programmed number of stop bits to each character. also, an even or odd parity bit is inserted prior to the stop bit(s), as defined by the mode instruction. the character is then transmitted as a serial data stream on the txd output. the serial data is shifted out on the falling edge of txc at a rate equal to 1, 1 M 16 or 1 M 64 times that of the txc , as defined by the mode instruction. break characters can be continuously sent to the txd if commanded to do so. when no data characters have been loaded into the ma28151 the txd output remains high (marking) unless a break (continuously low) has been programmed. 3.5 asynchronous mode (receive) the rxd line is normally high. a falling edge on this line triggers the beginning of a start bit. the validity of this start bit is checked by again strobing this bit at its nominal center (16x or 64x mode only). if a low is detected again, it is a valid start bit, and the bit counter will start counting. the bit counter thus locates the center of the data bits, the parity bit (if it exists) and the stop bits. if a parity error occurs, the parity error flag is set. data and parity bits are sampled on the rxd pin with the rising edge of rxc . if a low level is detected as the stop bit, the framing error flag will be set. the stop bit signals the end of a character. note that the receiver requires only one stop bit, regardless of the number of stop bits programmed. this character is then loaded into the parallel l/o buffer of the ma28151. the rxrdy pin is raised to signal the cpu that a character is ready to be fetched. if a previous character has not been fetched by the cpu, the present character replaces it in the l/o buffer, and the overrun error flag is raised (thus the previous character is lost). all of the error flags can be reset by an error reset instruction. the occurrence of any of these errors will not affect the operation of the ma28151.
ma28151 6/22 d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 s 2 s 1 ep pen l2 l1 b2 b1 baud rate fa c t o r s yn c mode (1x) (16x) (64x) 00 11 00 11 c hara c ter len g th 5 bits 6 bits 7 bits 8 bits 00 11 01 01 parity enable and s en s e 1 = enable 0 = disable 1 = even 0 = odd number o f s t o p bit s n o t valid 1 bit 1 1 / 2 bits 2 bits 00 11 01 01 figure 4: mode instruction format, asynchronous mode txd marking data bits d0-dx generated by ma28151 parity bit stop bits rxd data bits d0-dx does not appear on dbus parity bit stop bits programmed char. length figure 5: asynchronous mode
ma28151 7/22 figure 6: transmission format figure 7: receive format 3.6 synchronous mode (transmission) the txd output is continuously high until the cpu sends its first character to the ma28151 which usually is a sync character. when the cts line goes low, the first character is serially transmitted out. all characters are shifted out on the falling edge of txc . data is shifted out at the same rate as the txc . once transmission has started, the data stream at the txd output must continue at the txc rate. if the cpu does not provide the ma28151 with a data character before the ma28151 transmitter buffers become empty, the sync characters (or character if in single sync character mode) will be automatically inserted in the txd data stream. in this case, the txempty does not go low when the sync is being shifted out (see figure 8). the txempty pin is internally reset by a data character being written into the ma28151. 3.7 synchronous mode (receiver) in this mode character synchronisation can be internally or externally achieved. if the sync mode has been programmed, enter-hunt command should be included in the first command instruction word written. data on the rxd pin is then sampled on the rising edge of rxc . the content of the rx buffer is compared to every bit boundary with the first sync character until a match occurs. if the ma28151 has been programmed for two sync characters, the subsequent received character is also compared; when both sync characters have been detected, the usart ends the hunt mode and is in character synchronization. the syndet pin is then set high, and is reset automatically by a status read. if parity is programmed, syndet will not be set until the middle of the parity bit, instead of the middle of the last data bit. in the external sync mode, synchronization is achieved by applying a high level on the syndet pin, thus forcing the ma28151 out of the hunt mode. the high level can be removed after one rxc cycle. an enter hunt command has no effect in the asynchronous mode of operation. figure 8: sync character insertion parity bit data character stop bits start bit data character assembled serial data output (txd) cpu byte (5-8 bits/character) parity bit data character stop bits start bit data character serial data input (rxd) cpu byte (5-8 bits/character) (see note below) note: if character length is defined as 5, 6 or 7 bits the unused bits are set to zero.
ma28151 8/22 parity error and overrun error are both checked in the same way as in the asynchronous receive mode. parity is checked when not in hunt, regardless of whether the receiver is enabled or not. the cpu can command the receiver to enter the hunt mode if synchronisation is lost. this will also set all the used character bits in the buffer to a one thus preventing a possible false syndet caused by data that happens to be in the rx buffer at enter hunt time. note: the syndet flip-flop is reset at each status read, regardless of whether internal or external sync has been programmed. this does not cause the ma28151 to return to the hunt mode. when in sync mode, but not in hunt, sync detection is still functional, but only occurs at the known word boundaries. thus, if one status read indicates syndet and a second status read also indicates syndet, then the programmed syndet characters have been received since the previous status read. (if double character sync has been contiguously received to gate a syndet indication). when external syndet mode is selected, internal sync detect is disabled, and the syndet flip-flop may be set at any bit boundary. 3.9 data format, synchronous mode data characters assembled serial data output (txd) sync char 1 sync char 2 data characters figure 9: receive format, synchronous mode figure 10: data format, synchronous mode data characters cpu bytes (5-8 bits/character) sync char 1 sync char 2 data characters 3.8 mode instruction format, synchronous mode d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 ss e s ep pen l2 l1 0 0 c hara c ter len g th 5 bits 6 bits 7 bits 8 bits 00 11 01 01 parity enable and s en s e 1 = enable 0 = disable 1 = even 0 = odd external s yn c dete c t 1 = syncdet is an input 0 = syncdet is an output s in g le c hara c ter s yn c 1 = single sync char. 0 = double sync char. figure 11: mode instruction format, synchronous mode
ma28151 9/22 3.10 command instruction definition once the functional definition of the ma28151 has been programmed by the mode instruction and the sync characters are loaded (if in sync mode) then the device is ready to be used for data communications. the command instruction controls the actual operation of the selected format. functions such as: enable transmit/receive, error reset and modem controls are provided by the command instruction. once the mode instruction has been written into the ma28151 and sync characters inserted, if necessary, then all further control writes (cdn=1) will load a command instruction. a reset operation (internal or external) will return the ma28151 to the mode instruction format. note: internal reset on power-up. when power is first applied, the ma28151 may come up in the mode, sync character or command format. to guarantee that the device is in the command instruction format before the reset command is issued, it is safest to execute the worst-case initialization sequence (sync mode with two sync characters). loading three 00 h s consecutively into the device with cdn=1 configures sync operation and writes two dummy 00 h sync characters. an internal reset command (40 h ) may then be issued to return the device to the idle state. 3.11 command instruction format d 7 tran s mit enable 1 = enable 0 = disable eh d 6 ir d 5 rts d 4 er d 3 sbrk d 2 rxe d 1 dtr d 0 txen data terminal ready high will force dtr output to zero re c eive enable 1 = enable 0 = disable s end break c hara c ter 1 = forces txd low 0 = normal operation err o r re s et 1 = reset error flags pe, oe, fe re q ue s t t o s end high will force rts output to zero internal re s et high returns the ma28151 to mode instruction format enter hunt m o de* high enables search for sync characters (has no effect in async mode) *note: error reset must be performed whenever rxenable and enter-hunt are programmed. figure 12: command instruction format
ma28151 10/22 3.12 status read definition in data communication systems it is often necessary to examine the status of the active device to ascertain if errors have occurred or other conditions that require the processors attention. the ma28151 has facilities that allow the programmer to read the status of the device at any time during the functional operation. (status update is inhibited during status read). a normal read command is issued by the cpu with cdn high to accomplish this function. some of the bits in the status read format have identical meanings to external output pins so that the ma28151 can be used in a completely polled or interrupt-driven environment. txrdy is an exception. note that status update can have a maximum delay of 28 clock periods from the actual event affecting the status. 3.13 status read format d 7 d s r d 6 s yndet brkdet d 5 fe d 4 o e d 3 pe d 2 tx empty d 1 rxrdy d 0 txrdy parity err o r the pe flag is set when the parity error is detected. it is reset by the er bit of the command instruction. pe does not inhibit the operation of the ma28151. note 1: txrdy status bit has different meanings from the txrdy output pin. the former is not conditioned by cts and txen, the latter is conditioned by both cts and txen. ie. txrdy status bit 0 db buffer empty txrdy pin out = db buffer empty or (ctsn = 0) or (txen = 1) note 1 same as i/o pins o verrun err o r the oe flag is set when the cpu does not read a character before the next one becomes available. it is reset by the er bit of the command instruction oe does not inhibit operation of the ma28151, however the previously overrun character is lost. framin g err o r (a s yn c only) the fe flag is set when a valid stop bit is not detected at the end of every character. it is reset by the er bit of the command instruction. fe does not inhibit the operation of the ma28151. data s et ready indicates that the dsr is at a zero level. figure 13: status read format
ma28151 11/22 4. timing waveforms figure 14: system clock input figure 15: transmitter clock and data figure 16: receive clock and data
ma28151 12/22 figure 17: write data cycle (cpu to usart) figure 19: write control or output port cycle (cpu to usart) note: t wc includes the response timing of a control byte. figure 18: read data cycle (usart to cpu)
ma28151 13/22 figure 20: read control or output port cycle (usart to cpu) note: t cr includes the effect of cts on the txenable circuitary. figure 21: transmitter control and flag timing (async mode) example format = 7 bit character with parity and 2 stop bits.
ma28151 14/22 figure 22: receiver control and flag timing (async mode) example format = 7 bit character with parity and 2 stop bits.
ma28151 15/22 5. ac electrical characteristics symbol parameter min. max. units condition t cy internal clock cycle time 200 1000 ns notes 1, 5, 6 t 0 external clock high pulse width 25 - ns - t 0 external clock low pulse width 25 - ns - t r , t f clock rise and fall time - 10 ns - t dtx txd delay from falling edge of txd - 1 m s- t tpw transmitter input clock pulse width 12xt cy - - 1 x baud rate 1xt cy - - 16 x and 64 x baud rate t tpd transmitter input clock pulse delay 15xt cy - - 1 x baud rate 3xt cy - - 16 x and 64 x baud rate t rpw receive input clock pulse width 12xt cy - - 1 x baud rate 1xt cy - - 16 x and 64 x baud rate t rpd receive input clock pulse delay 15xt cy - - 1 x baud rate 3xt cy - - 16 x and 64 x baud rate t txrdy txrdy pin delay from center of last bit - 8xt cy - note 7 t txrdy clear txrdy fall from falling dsn (write) - 45 - note 7 t rxrdy rxrdy pin delay from center of last bit - 26xt cy - note 7 t rxrdy clear rxrdy fall from falling dsn (read) - 45 - note 7 t txempty txempty from centre of last bit 20xt cy - - note 7 t wc control delay from rising edge of write 8xt cy - - note 7 t cr control to read set-up time ( dsr , cts ) 20xt cy - - note 7 t ar address stable before dsn (csn, cdn) 0 - ns note 2 t ra address hold time before dsn (csn, cdn) 0 - ns note 2 t rr dsn pulse width 20 - ns - t rd data delay from dsn falling (read) - 30 ns note 3 t df dsn rising to data floating (read) 10 45 ns note 8 t dw data set-up time to dsn rising (write) 15 - ns - t wd data hold time to dsn rising (write) 5 - ns - t rv recovery time between writes (not shown) 6xt cy - - note 4 notes: 1. ac timings measured v oh = 1.5 v ol = 1.5. 2. csn and command/data are considered as addresses. 3. assumes that address is valid before dsn goes low. 4. this recovery time is for mode initialisation only. write data is allowed when txrdy = 1. recovery time between writes for asynchronous mode is 8xt cy and for synchronous mode is 16xt cy . 5. the txc and rxc frequencies have the following limitation with respect to clock: for 1 x baudrate, f tx or f rx 1/ (30t cy ): for 16 x and 64 x baud rate, f tx or f rx 1/(4.5t cy ). 6. reset pulse width = 6t cy minimum; system clock must be running during reset. 7. status update can have a maximum delay of 28 clock periods from the event affecting the status. 8. data bus connected to v dd via loads of 680 w (minimum). mil-std-883, method 5005, subgroups 9, 10, 11 figure 23: ac electrical characteristics symbol parameter min. max. units condition - clock frequency (osc) - 20 mhz - f tx transmitter input clock frequency dc 64 khz 1 x baud rate dc 310 khz 16 x baud rate dc 615 khz 64 x baud rate f rx receiver input clock frequency dc 64 khz 1x baud rate dc 310 khz 16 x baud rate dc 615 khz 64 x baud rate mil-std-883, method 5005, subgroups 7, 8a, 8b figure 24: operating ac electrical characteristics
ma28151 16/22 6. dc characteristics and ratings parameter min max units supply voltage -0.5 7 v input voltage -0.3 v dd +0.3 v current through any pin -20 +20 ma operating temperature -55 125 c storage temperature -65 150 c note: stresses above those listed may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these conditions, or at any other condition above those indicated in the operations section of this specification, is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. figure 25: absolute maximum ratings total dose radiation not exceeding 3x10 5 rad(si) symbol parameter conditions min typ max units v dd supply voltage - 4.5 5.0 5.5 v v ih input high voltage - 2.2 - - v v il input low voltage - - - 0.8 v v oh output high voltage i oh = -2ma v dd -0.5 - - v v ol output low voltage i ol = 5ma - - v ss +0.4 v i in input leakage current (note 1) v dd = 5.5v, - - 10 m a v in = v ss or v dd i oz tristate leakage current (note 1) v dd = 5.5v, - - 50 m a v in = v ss or v dd i dd power supply current static, v dd = 5.5v - 0.1 10 ma v dd = 5v 10%, over full operating temperature range. mil-std-883, method 5005, subgroups 1, 2, 3 note 1: guaranteed but not tested at -55 c figure 26: electrical characteristics subgroup definition 1 static characteristics specified in figure 26 at +25 c 2 static characteristics specified in figure 26 at +125 c 3 static characteristics specified in figure 26 at -55 c 7 functional characteristics specified in figure 24 at +25 c 8a functional characteristics specified in figure 24 at +125 c 8b functional characteristics specified in figure 24 at -55 c 9 switching characteristics specified in figure 23 at +25 c 10 switching characteristics specified in figure 23 at +125 c 11 switching characteristics specified in figure 23 at -55 c figure 27: definition of mil-std-883, method 5005 subgroups
ma28151 17/22 7. outlines and pin assignments d w a e b z h a 1 15 m e c e 1 seating plane 1 14 28 15 ref millimetres inches min. nom. max. min. nom. max. a - - 5.715 - - 0.225 a1 0.38 - 1.53 0.015 - 0.060 b 0.35 - 0.59 0.014 - 0.023 c 0.20 - 0.36 0.008 - 0.014 d - - 36.02 - - 1.418 e - 2.54 typ. - - 0.100 typ. - e1 - 15.24 typ. - - 0.600 typ. - h 4.71 - 5.38 0.185 - 0.212 me - - 15.90 - - 0.626 z - - 1.27 - - 0.050 w - - 1.53 - - 0.060 xg404 28 d1 27 d0 26 vdd 25 rxc 24 dtr 23 rts 22 dsr 21 reset 20 clk 19 txd 18 txe 17 cts 16 syndet 15 txrdy 1 d2 2 d3 3 rxd 4 gnd 5 d4 6 d5 7 d6 8 d7 9 txc 10 rdwn 11 csn 12 cdn 13 dsn 14 rxrd y top view figure 28: 28-lead ceramic dil (solder seal) - package style c
ma28151 18/22 figure 29: 48-pad leadless chip carrier - package style l bottom view pad 1 radius r 3 corners e z e b 1 d a ref millimetres inches min. nom. max. min. nom. max. a - - 2.29 - - 0.090 b1 - 0.51 - - 0.020 - d - - 14.60 - - 0.575 e - - 14.60 - - 0.575 e - 1.02 - - 0.040 - z - 1.52 typ. - - 0.060 typ. - xg431 bottom view 19 18 17 16 15 14 13 12 11 10 9 8 7 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 6 5 4 3 2 1 48 47 46 45 44 43 n c c dn d s n rxrdy n c n c txrdy s yndet n c cts txempty n c n c g nd rxd d3 n c d2 n c n c d1 d0 n c vdd nc d4 d5 nc d6 nc d7 nc txc rdw n csn nc nc rxc nc dtr rts nc dsr nc reset clk txd nc
ma28151 19/22 top view j1 d1 l pin 1 j2 b e d2 z a1 a c ref millimetres inches min. nom. max. min. nom. max. a - - 2.72 - - 0.107 a1 1.83 - 2.24 0.072 - 0.088 b 0.41 - 0.51 0.016 - 0.020 c 0.20 - 0.30 0.008 - 0.012 d1, d2 23.88 - 24.51 0.940 - 0.960 e - 2.54 - - 0.050 - j1 - 1.02 - - 0.040 - j2 - 0.51 - - 0.020 - l 10.16 - 10.54 0.400 - 0.415 z 1.65 - 2.16 0.065 - 0.085 xg540 figure 30a: 68-lead topbraze flatpack - package style f
ma28151 20/22 figure 30b: 68-lead topbraze flatpack - package style f top view 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 nc nc cdn nc dsn nc rxrdy nc txrd y nc syndet nc cts nc txe nc nc nc nc csn nc rdwn nc txc nc d7 nc d6 nc d5 nc d4 nc nc nc txd nc clk nc r eset nc dsr nc rts nc dtr nc rxc nc
ma28151 21/22 8. radiation tolerance total dose radiation testing for product procured to guaranteed total dose radiation levels, each wafer lot will be approved when all sample devices from each lot pass the total dose radiation test. the sample devices will be subjected to the total dose radiation level (cobalt-60 source), defined by the ordering code, and must continue to meet the electrical parameters specified in the data sheet. electrical tests, pre and post irradiation, will be read and recorded. dynex semiconductor can provide radiation testing compliant with mil-std-883 ionizing radiation (total dose) test 1019. 9. ordering information for details of reliability, qa/qc, test and assembly options, see manufacturing capability and quality assurance standards section 9. unique circuit designator s r q h radiation hard processing 100 krads (si) guaranteed 300 krads (si) guaranteed 1000 krads (si) guaranteed radiation tolerance c f l ceramic dil (solder seal) flatpack (solder seal) leadless chip carrier package type qa/qci process (see section 9 part 4) test process (see section 9 part 3) assembly process (see section 9 part 2) l c d e b s rel 0 rel 1 rel 2 rel 3/4/5/stack class b class s reliability level max28151xxxxx total dose (function to specification)* 3x10 5 rad(si) transient upset (stored data loss) 5x10 10 rad(si)/sec transient upset (survivability) >1x10 12 rad(si)/sec neutron hardness (function to specification) >1x10 15 n/cm 2 single event upset** <1x10 -10 errors/bit day latch up not possible * other total dose radiation levels available on request ** worst case galactic cosmic ray upset - interplanetary/high altitude orbit figure 31: radiation hardness parameters
ma28151 22/22 customer service centres france, benelux, italy and spain tel: +33 (0)1 69 18 90 00. fax: +33 (0)1 64 46 54 50 north america tel: 011-800-5554-5554. fax: 011-800-5444-5444 uk, germany, scandinavia & rest of world tel: +44 (0)1522 500500. fax: +44 (0)1522 500020 sales offices france, benelux, italy and spain tel: +33 (0)1 69 18 90 00. fax: +33 (0)1 64 46 54 50 germany tel: 07351 827723 north america tel: (613) 723-7035. fax: (613) 723-1518. toll free: 1.888.33.dynex (39639) / tel: (831) 440-1988. fax: (831) 440-1989 / tel: (949) 733-3005. fax: (949) 733-2986. uk, germany, scandinavia & rest of world tel: +44 (0)1522 500500. fax: +44 (0)1522 500020 these offices are supported by representatives and distributors in many countries world-wide. ? dynex semiconductor 2000 publication no. ds3574-5 issue no. 5.0 january 2000 technical documentation C not for resale. printed in united kingdom headquarters operations dynex semiconductor ltd doddington road, lincoln. lincolnshire. ln6 3lf. united kingdom. tel: 00-44-(0)1522-500500 fax: 00-44-(0)1522-500550 dynex power inc. unit 7 - 58 antares drive, nepean, ontario, canada k2e 7w6. tel: 613.723.7035 fax: 613.723.1518 toll free: 1.888.33.dynex (39639) this publication is issued to provide information only which (unless agreed by the company in writing) may not be used, applied or reproduced for any purpose nor form part of any order or contract nor to be regarded as a representation relating to the products or services concerned. no warranty or guarantee express or implied is made regard ing the capability, performance or suitability of any product or service. the company reserves the right to alter without prior notice the specification, design or price of any product or service. information con cerning possible methods of use is provided as a guide only and does not constitute any guarantee that such methods of use will be satisfactory in a specific piece of equipment. it is the user's responsibility to f ully determine the performance and suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. these products are not suitable for use in any medical products whose failure to perform may result in significant injury or death to the user. all products and materials are sold and services provided subject to the company's conditions of sale, w hich are available on request. all brand names and product names used in this publication are trademarks, registered trademarks or trade names of their respec tive owners. http://www.dynexsemi.com e-mail: power_solutions@dynexsemi.com datasheet annotations: dynex semiconductor annotate datasheets in the top right hard corner of the front page, to indicate product status. the annota tions are as follows:- target information: this is the most tentative form of information and represents a very preliminary specification. no actual design work on the product has been started. preliminary information: the product is in design and development. the datasheet represents the product as it is understood but details may change. advance information: the product design is complete and final characterisation for volume production is well in hand. no annotation: the product parameters are fixed and the product is available to datasheet specification.

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