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* other brands and names are the property of their respective owners. information in this document is provided in connection with intel products. intel assumes no liability whatsoever, including infringement of any patent or copyright, for sale and use of intel products except as provided in intel's terms and conditions of sale for such products. intel retains the right to make changes to these specifications at any time, without notice. microcomputer products may have minor variations to this specification known as errata. february 1994 copyright ? intel corporation, 1995 order number: 270849-004 87c54/87c54-20 chmos single-chip 8-bit microcontroller with 16 kbytes user programmable eprom automotive y extended automotive temperature range ( b 40 cto a 125 c ambient) y high performance chmos eprom y three 16-bit timer/counters y one-to-three level program/data lock system y 16k on-chip eprom/rom y 256 bytes of on-chip data ram y quick pulse programming algorithm y boolean processor y 32 programmable i/o lines y 7 interrupt sources y programmable serial channel with: e framing error detection e automatic address recognition y ttl and cmos compatible logic levels y 64k external program memory space y 64k external data memory space y mcs -51 compatible instruction set y power saving idle and power down modes y once (on-circuit emulation) mode y rfi reduction mode y available in 12 mhz, 16 mhz and 20 mhz versions y available in plcc and dip packages (see packaging spec., order y 231369) memory organization program memory: up to 16 kbytes of the program memory can reside in the on-chip eprom. the device can also address up to 64k of program memory external to the chip. data memory: this microcontroller has a 25 6 x 8 on-chip ram. in addition it can address up to 64 kbytes of external data memory. the intel 87c54 is a single-chip control-oriented microcontroller which is fabricated on intel's reliable chmos eprom technology. being a member of the mcs-51 family, the 87c54 uses the same powerful instruction set, has the same architecture, and is pin-for-pin compatible with the existing mcs-51 family of products. the 87c54 is an enhanced version of the 87c51fb. its added features of 16 kbytes of program memory make it an even more powerful microcontroller for applications that require high speed i/o and up/down counting capabilities such as brake and traction control.
automotive 87c54/87c54-20 270849 1 figure 1. 87c54 block diagram 2
automotive 87c54/87c54-20 87c54 product options intel's extended and automotive temperature range products are designed to meet the needs of those applications whose operating requirements exceed commercial standards. with the commercial standard temperature range, operational characteristics are guaranteed over the temperature range of 0 cto a 70 c ambient. with the extended temperature range option, operational characteristics are guaranteed over the temperature range of b 40 cto a 85 c ambient. for the automo- tive temperature range option, operational charac- teristics are guaranteed over the temperature range of b 40 cto a 125 c ambient. the automotive, ex- tended, and commercial temperature versions of the mcs-51 product families are available with or with- out burn-in options. as shown in figure 2 temperature, burn-in, and package options are identified by a one- or two-letter prefix to the part number. 270849 4 * example: AN87C54 indicates an automotive temperature range version of the 87c54 in a plcc package with 16 kbyte eprom program memory. figure 2. package options table 1. temperature options temperature temperature operating burn-in classification designation temperature options c ambient extended t b 40 to a 85 standard l b 40 to a 85 extended automotive a b 40 to a 125 standard b b 40 to a 125 extended 3
automotive 87c54/87c54-20 packages part prefix package type 87c54 ap 40-pin plastic dip 87c54 an 44-pin plcc 270849 2 dip (pdip) 270849 3 * do not connect reserved pins. pad (plcc) figure 3. pin connections pin descriptions v cc : supply voltage. v ss : circuit ground. v ss1 : secondary ground (in plcc only). provided to reduce ground bounce and improve power supply by-passing. note: this pin is not a substitute for the v ss pin (pin 22). port 0: port 0 is an 8-bit, open drain, bidirectional i/o port. as an output port each pin can sink several ls ttl inputs. port 0 pins that have 1's written to them float, and in that state can be used as high-imped- ance inputs. port 0 is also the multiplexed low-order address and data bus during accesses to external program and data memory. in this application it uses strong inter- nal pullups when emitting1's, and can source and sink several ls ttl inputs. port 0 also receives the code bytes during eprom programming, and outputs the code bytes during program verification. external pullup resistors are re- quired during program verification. port 1: port 1 is an 8-bit bidirectional i/o port with internal pullups. the port 1 output buffers can drive ls ttl inputs. port 1 pins that have 1's written to them are pulled high by the internal pullups, and in that state can be used as inputs. as inputs, port 1 pins that are externally pulled low will source current (i il , on the data sheet) because of the internal pull- ups. in addition, port 1 serves the functions of the follow- ing special features of the 87c54: port pin alternate function p1.0 t2 (external count input to timer/ counter 2), clock-out p1.1 t2ex (timer/counter 2 capture/ reload trigger and direction control) p1.2 eci (external count input to the pca) p1.3 cex0 (external i/o for compare/ capture module 0) p1.4 cex1 (external i/o for compare/ capture module 1) p1.5 cex2 (external i/o for compare/ capture module 2) p1.6 cex3 (external i/o for compare/ capture module 3) p1.7 cex4 (external i/o for compare/ capture module 4) port 1 receives the low-order address bytes during eprom programming and verifying. port 2: port 2 is an 8-bit bidirectional i/o port with internal pullups. the port 2 output buffers can drive ls ttl inputs. port 2 pins that have 1's written to them are pulled high by the internal pullups, and in that state can be used as inputs. as inputs, port 2 pins that are externally pulled low will source current (i il , on the data sheet) because of the internal pull- ups. 4
automotive 87c54/87c54-20 port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (movx @ dptr). in this application it uses strong internal pullups when emitting 1's. dur- ing accesses to external data memory that use 8-bit addresses (movx @ ri), port 2 emits the contents of the p2 special function register. some port 2 pins receive the high-order address bits during eprom programming and program verifica- tion. port 3: port 3 is an 8-bit bidirectional i/o port with internal pullups. the port 3 output buffers can drive ls ttl inputs. port 3 pins that have 1's written to them are pulled high by the internal pullups, and in that state can be used as inputs. as inputs, port 3 pins that are externally pulled low will source current (i il , on the data sheet) because of the pullups. port 3 also serves the functions of various special features of the mcs-51 family, as listed below: port pin alternate function p3.0 rxd (serial input port) p3.1 txd (serial output port) p3.2 int0 (external interrupt 0) p3.3 int1 (external interrupt 1) p3.4 t0 (timer 0 external input) p3.5 t1 (timer 1 external input) p3.6 wr (external data memory write strobe) p3.7 rd (external data memory read strobe) in addition, some port 3 pins receive the high-order address bits and act as control signals during eprom programming and programming verification. rst: reset input. a high on this pin for two machine cycles while the oscillator is running resets the de- vice. the port pins will be driven to their reset condi- tion when a minimum v ih1 is applied, whether the oscillator is running or not. an internal pulldown re- sistor permits a power-on reset with only a capacitor connected to v cc . ale: address latch enable output pulse for latching the low byte of the address during accesses to ex- ternal memory. this pin (ale/prog ) is also the program pulse input during eprom programming for the 87c54. in normal operation ale is emitted at a constant rate of (/6 the oscillator frequency, and may be used for external timing or clocking purposes. note, how- ever, that one ale pulse is skipped during each ac- cess to external data memory. throughout the remainder of this data sheet, ale will refer to the signal coming out of the ale/prog pin, and the pin will be referred to as the ale/prog pin. psen : program store enable is the read strobe to external program memory. when the 87c54 is executing code from external program memory, psen is activated twice each machine cycle, except that two psen activations are skipped during each access to external data memory. ea /v pp : external access enable. ea must be strapped to vss in order to enable the device to fetch code from external program memory locations 0000h to 0ffffh. note, however, that if any of the lock bits are programmed, ea will be internally latched on reset. ea should be strapped to v cc for internal program executions. this pin also receives the programming supply volt- age (v pp ) during eprom programming. xtal1: input to the inverting oscillator amplifier. xtal2: output from the inverting oscillator amplifier. oscillator characteristics xtal1 and xtal2 are the input and output, respec- tively, of a inverting amplifier which can be config- ured for use as an on-chip oscillator, as shown in figure 4. either a quartz crystal or ceramic resonator may be used. more detailed information concerning the use of the on-chip oscillator is available in appli- cation note ap-155, ``oscillators for microcontrol- lers.'' 5
automotive 87c54/87c54-20 270849 5 c1, c2 e 30 pf g 10 pf for crystals for ceramic resonators, contact resonator manufacturer. figure 4. oscillator connections to drive the device from an external clock source, xtal1 should be driven, while xtal2 floats, as shown in figure 5. there are no requirements on the duty cycle of the external clock signal, since the in- put to the internal clocking circuitry is through a di- vide-by-two flip-flop, but minimum and maximum high and low times specified on the data sheet must be observed. an external oscillator may encounter as much as a 100 pf load at xtal1 when it starts up. this is due to interaction between the amplifier and its feedback capacitance. once the external signal meets the v il and v ih specifications the capacitance will not ex- ceed 20 pf. 270849 6 figure 5. external clock drive configuration idle mode the user's software can invoke the idle mode. when the microcontroller is in this mode, power consump- tion is reduced. the special function registers and the onboard ram retain their values during idle, but the processor stops executing instructions. idle mode will be exited if the chip is reset or if an en- abled interrupt occurs. power down mode to save even more power, a power down mode can be invoked by software. in this mode, the oscillator is stopped and the instruction that invoked power down is the last instruction executed. the on-chip ram and special function registers retain their val- ues until the power down mode is terminated. on the 87c54 either a hardware reset or an external interrupt can cause an exit from power down. reset redefines all the sfrs but does not change the on- chip ram. an external interrupt allows both the sfrs and on-chip ram to retain their values. to properly terminate power down the reset or ex- ternal interrupt should not be executed before v cc is restored to its normal operating level and must be held active long enough for the oscillator to restart and stabilize (normally less than 10 ms). with an external interrupt, int0 or int1 must be en- abled and configured as level-sensitive. holding the pin low restarts the oscillator but bringing the pin back high completes the exit. (the oscillator must be allowed time to stabilize after start up, before this pin is released high.) once the interrupt is serviced, the next instruction to be executed after reti will be the one following the instruction that put the device into power down. design consideration when the idle mode is terminated by a hardware reset, the device normally resumes program execu- tion, from where it left off, up to two machine cycles before the internal reset algorithm takes control. on- chip hardware inhibits access to internal ram in this event, but access to the port pins is not inhibited. to eliminate the possibility of an unexpected write when idle is terminated by reset, the instruction following the one that invokes idle should not be one that writes to a port pin or to external memory. 6
automotive 87c54/87c54-20 once mode the once (``on-circuit emulation'') mode facilitates testing and debugging of systems using the 87c54 without the 87c54 having to be removed from the circuit. the once mode is invoked by: 1) pull ale low while the device is in reset and psen is high; 2) hold ale low as rst is deactivated. while the device is in once mode, the port 0 pins float and the other port pins and ale and psen are weakly pulled high. the oscillator circuit remains ac- tive. while the 87c54 is in this mode, an emulator or test cpu can be used to drive the circuit. normal operation is restored when a normal reset is applied. rfi reduction mode the rfi reduction feature can be used only if exter- nal program memory is not required since this mode disables the ale pin during instruction code fetches. by writing a logical one to the lsb of the auxiliary register (address 08eh), the ale is disabled for in- struction code fetches and the output is weakly held high. when a logical zero is written, the ale pin is enabled allowing it to generate the address latch enable signal. this bit is cleared by reset. once dis- abled, ale remains disabled until it is reset by soft- ware or until a hardware reset occurs. table 2. status of the external pins during idle and power down mode program ale psen port0 port1 port2 port3 memory idle internal 1 1 data data data data idle external 1 1 float data address data power down internal 0 0 data data data data power down external 0 0 float data data data note: for more detailed information on the reduced power modes refer to current embedded applications handbook, and applica- tion note ap-252, ``designing with the 80c51bh.'' 7
automotive 87c54/87c54-20 absolute maximum ratings * ambient temperature under bias b 40 cto a 125 c storage temperature b 65 cto a 150 c voltage on ea/v pp pin to v ss 0v to a 13.0v voltage on any other pin to v ss b 0.5v to a 6.5v i ol per i/o pin 15 ma power dissipation1.5w (based on package heat transfer limitations, not device power consumption) typical junction temperature a 135 c (based on ambient temperature at a 125 c) typical thermal resistance junction-to-ambient ( i ja ): pdip 45 c/w plcc 46 c/w notice: this data sheet contains information on products in the sampling and initial production phases of development. the specifications are subject to change without notice. verify with your local intel sales office that you have the latest data sheet be- fore finalizing a design. * warning: stressing the device beyond the ``absolute maximum ratings'' may cause permanent damage. these are stress ratings only. operation beyond the ``operating conditions'' is not recommended and ex- tended exposure beyond the ``operating conditions'' may affect device reliability. advanced informationecontact intel for design-in information dc characteristics: (t a eb 40 cto a 125 c; v cc e 5v g 20%; v ss e 0v) symbol parameter min typ max unit test conditions (note 4) v il input low voltage b 0.5 0.2 v cc b 0.1 v v il1 input low voltage ea 0 0.2 v cc b 0.3 v v ih input high voltage 0.2 v cc a 0.9 v cc a 0.5 v (except xtal1, rst, ea ) v ih1 input high voltage (xtal1, rst) 0.7 v cc a 0.1v v cc a 0.5 v v ol output low voltage (note 5) 0.3 v i ol e 100 m a (note 1) (ports 1, 2 and 3) 0.45 v i ol e 1.6 ma (note 1) 1.0 v i ol e 3.5 ma (note 1, 4) v ol1 output low voltage (note 5) 0.3 v i ol e 200 m a (note 1) (port 0, ale, psen ) 0.45 v i ol e 3.2 ma (note 1) 1.0 v i ol e 7.0 ma (note 1, 4) v oh output high voltage v cc b 0.3 v i oh eb 10 m a (ports 1, 2 and 3) v cc b 0.7 v i oh eb 30 m a v cc b 1.5 v i oh eb 60 m a v oh1 output high voltage v cc b 0.5 v i oh eb 200 m a (port 0 in external bus mode) v cc b 0.7 v i oh eb 3.2 ma (note 4) v cc b 1.5 v i oh eb 7.0 ma i il logical 0 input current b 75 m av in e 0.45v (ports 1, 2 and 3) i li input leakage current (port 0) g 10 m av il max k v in k v cc i tl logical 1 to 0 transition current b 750 m av in e 2v (ports 1, 2 and 3) rrst rst pulldown resistor 40 225 k x cio pin capacitance 10 pf @ 1 mhz, 25 c i cc power supply current: (note 3) running at 16/20 mhz (figure 5) 20/25 28/33 ma idle mode at 16/20 mhz (figure 5) 5 12/14 ma power down mode 15 100 m a 8
automotive 87c54/87c54-20 notes: 1. capacitive loading on ports 0 and 2 may cause noise pulses to be superimposed on the v ol s of ale and ports 1, 2 and 3. the noise is due to external bus capacitance discharging into the port 0 and port 2 pins when these pins make 1 to 0 transitions during bus operations. in applications where capacitance loading exceeds 100 pfs, the noise pulse on the ale signal may exceed 0.8v. in these cases, it may be desirable to qualify ale with a schmitt trigger, or use an address latch with a schmitt trigger strobe input. 2. capacitive loading on ports 0 and 2 cause the v oh on ale and psen to drop below the 0.9 v cc specification when the address lines are stabilizing. 3. see figures 6 9 for test conditions. minimum v cc for power down is 2v. 4. typicals are based on limited number of samples and are not guaranteed. the values listed are at room temperature and 5v. 5. under steady state (non-transient) conditions, i ol must be externally limited as follows: maximum i ol per port pin: 10ma maximum i ol per 8-bit porte port 0: 26 ma ports 1, 2 and 3: 15 ma maximum total i ol for all output pins: 71 ma if i ol exceeds the test condition, v ol may exceed the related specification. pins are not guaranteed to sink current greater than the listed test conditions. 270849 7 i cc max at other frequencies is given by: active mode i cc max e (1.25 c osc freq) a 8 idle mode i cc max e (0.5 c osc freq) a 4 where osc freq is in mhz, i cc is in ma. figure 6. i cc vs frequency 270849 8 all other pins disconnected tclch e tchcl e 5ns figure 7. i cc test condition, active mode 270849 9 all other pins disconnected tclch e tchcl e 5ns figure 8. i cc test condition idle mode 270849 10 all other pins disconnected figure 9. i cc test condition, power down mode. v cc e 2.0v to 6.0v. 270849 11 figure 10. clock signal waveform for i cc tests in active and idle modes. tclch e tchcl e 5 ns. 9
automotive 87c54/87c54-20 explanation of the ac symbols each timing symbol has 5 characters. the first char- acter is always a `t' (stands for time). the other characters, depending on their positions, stand for the name of a signal or the logical status of that signal. the following is a list of all the characters and what they stand for. a: address c: clock d: input data h: logic level high i: instruction (program memory contents) l: logic level low, or ale p: psen q: output data r: rd signal t: time v: valid w: wr signal x: no longer a valid logic level z: float for example, t avll e time from address valid to ale low t llpl e time from ale low to psen low ac characteristics (t a eb 40 cto a 125 c, v cc e 5v g 20%, v ss e 0v, load capacitance for port 0, ale/prog and psen e 100 pf, load capacitance for all other outputs e 80 pf) advanced informationecontact intel for design-in information external memory characteristics 12 mhz oscillator variable oscillator symbol parameter 87c54/87c54-20 units min max min max 1/t clcl oscillator 3.5 16/20 mhz frequency t lhll ale pulse width 127 2 t clcl b 40 ns t avll address valid to 43 t clcl b 40 ns ale low t llax address hold after 53 t clcl b 30 ns ale low t lliv ale low to valid 234 4 t clcl b 100/ ns instruction in 4t clcl b 75 * t llpl ale low to psen 53 t clcl b 30 ns low t plph psen pulse width 205 3 t clcl b 45 ns t pliv psen low to valid 145 3 t clcl b 105/ ns instruction in 3t clcl b 90 * t pxix input instruction 0 0 ns hold after psen t pxiz input instruction 59 t clcl b 25/ ns float after psen t clcl b 20 * t aviv address valid to 312 5 t clcl b 105 ns valid instruction in t plaz psen low to 10 10 ns address float 10
automotive 87c54/87c54-20 external memory characteristics (continued) 12 mhz oscillator variable oscillator symbol parameter 87c54/87c54-20 units min max min max t rlrh rd pulse width 400 6 t clcl b 100 ns t wlwh wr pulse width 400 6 t clcl b 100 ns t rldv rd low to valid 252 5 t clcl b 165/ ns data in 5t clcl 95 * t rhdx data hold after rd 00ns high t rhdz data float after rd 107 2 t clcl b 60 ns high t lldv ale low to valid 517 8 t clcl b 150/ ns data in 8t clcl b 90 * t avdv address valid to 585 9 t clcl b 165/ ns valid data in 9t clcl b 90 * t llwl ale low to rd or 200 300 3 t clcl b 50 3 t clcl a 50 ns wr low t avwl address valid to 203 4 t clcl b 130/ ns wr low 4t clcl b 90 * t qvwx data valid before 33 t clcl b 50/ ns wr low t clcl b 35 * t whqx data hold after wr 33 t clcl b 50/ ns high t clcl b 40 * t qvwh data valid to wr 433 7 t clcl b 150/ ns high 7t clcl b 70 * t rlaz rd low to address 0 0 ns float t whlh rd or wr high to 43 123 t clcl b 40 t clcl a 40 ns ale high note: * timings speicified for the 87c54-20 are valid at 20 mhz only. for timings below 20 mhz, use the 87c54 timings. 11
automotive 87c54/87c54-20 external program memory read cycle 270849 12 external data memory read cycle 270849 13 external data memory write cycle 270849 14 12
automotive 87c54/87c54-20 serial port timingeshift register mode test conditions: t a eb 40 cto a 125 c; v cc e 5v g 20%; v ss e 0v; load capacitance e 80 pf symbol parameter 12 mhz oscillator variable oscillator units min max min max t xlxl serial port clock cycle time 1 12t clcl m s t qvxh output data setup to clock 700 10t clcl b 133 ns rising edge t xhqx output data hold after 50 2t clcl b 117 ns clock rising edge t xhdx input data hold after clock 0 0 ns rising edge t xhdv clock rising edge to input 700 10t clcl b 133 ns data valid shift register mode timing waveforms 270849 15 external clock drive symbol parameter min max units 1/t clcl oscillator frequency 87c54 3.5 16/20 mhz t chcx high time 20 ns t clcx low time 20 ns t clch rise time 20 ns t chcl fall time 20 ns external clock drive waveforms 270849 16 13
automotive 87c54/87c54-20 ac testing input, output waveforms 270849 17 ac inputs during testing are driven at v cc b 0.5v for a logic ``1'' and 0.45v for a logic ``0''. timing measurements are made at v ih min for a logic ``1'' and v il max for a logic ``0''. float waveforms 270849 18 for timing purposes a port pin is no longer floating when a 100 mv change from load voltage occurs, and begins to float when a 100 mv change from the loaded v oh /v ol level occurs. i ol /i oh t g 20 ma. eprom characteristics table 3 shows the logic levels for programming the program memory, the encryption table and the lock bits and for reading the signature bytes. table 3. eprom programming modes mode rst psen ale/ ea / p2.6 p2.7 p3.3 p3.6 p3.7 prog v pp program code data h l ? 12.75v l h h h h verify code data h l h h l l l h h program encryption h l ? 12.75v l h h l h array address 0 3fh program lock bit 1 h l ? 12.75v h h h h h bits bit 2 h l ? 12.75v h h h l l bit 3 h l ? 12.75v h l h h l read signature byte h l h h l l l l l definition of terms address lines: p1.0 p1.7, p2.0 p2.5 respec- tively for a0 a13. data lines: p0.0 p0.7 for d0 d7. control signals: rst, psen , p2.6, p2.7, p3.3, p3.6, p3.7 program signals: ale/prog ,ea /v pp programming the eprom to be programmed, the part must be running with a 4 mhz to 6 mhz oscillator. (the reason the oscillator needs to be running is that the internal bus is being used to transfer address and program data to appro- priate internal eprom locations.) the address of an eprom location to be programmed is applied to port 1 and pins p2.0 p2.5 of port 2, while the code byte to be programmed into that location is applied to port 0. the other port 2 and 3 pins, rst, psen , and ea /v pp should be held at the ``program'' levels indicated in table 3. ale/prog is pulsed low to program the code byte into the addressed eprom location. the setup is shown in figure 11. 14
automotive 87c54/87c54-20 normally ea /v pp is held at logic high until just be- fore ale/prog is to be pulsed. then ea /v pp is raised to v pp , ale/prog is pulsed low, and then ea /v pp is returned to a valid high voltage. the volt- age on the ea /v pp pin must be at the valid ea /v pp high level before a verify is attempted. waveforms and detailed timing specifications are shown in later sections of this data sheet. note that the ea /v pp pin must not be allowed to go above the maximum specified v pp level for any amount of time. even a narrow glitch above that volt- age level can cause permanent damage to the de- vice. the v pp source should be well regulated and free of glitches. 270849 19 * see table 3 for proper input on these pins figure 11. programming the eprom quick pulse programming algorithm the 87c54 can be programmed using the quick pulse programming algorithm for microcontrollers. the features of the new programming method are a lower v pp (12.75v as compared to 21v) and a short- er programming pulse. it is possible to program the entire 16k bytes of eprom memory in less than 50 seconds with this algorithm! to program the part using the new algorithm, v pp must be 12.75v g 0.25v. ale/prog is pulsed low for 100 m s, 25 times as shown in figure 12. then, the byte just programmed may be verified. after pro- gramming, the entire array should be verified. the program lock features are programmed using the same method, but with the setup as shown in table 3. the only difference in programming program lock features is that the program lock features cannot be directly verified. instead, verification of programming is by observing that their features are enabled. program verification if the program lock bits have not been pro- grammed, the on-chip program memory can be read out for verification purposes, if desired, either during or after the programming operation. the address of the program memory location to be read is applied to port 1 and pins p2.0 p2.5. the other pins should be held at the ``verify'' levels indicated in table 3. the contents of the addressed locations will come out on port 0. external pullups are required on port 0 for this operation. if the encryption array in the eprom has been pro- grammed, the data present at port 0 will be code data xnor encryption data. the user must know the encryption array contents to manually ``unen- crypt'' the data during verify. the setup, which is shown in figure 13, is the same as for programming the eprom except that pin p2.7 is held at a logic low, or may be used as an active low read strobe. 15
automotive 87c54/87c54-20 270849 22 figure 12. prog waveforms 270849 23 figure 13. verifying the eprom 16
automotive 87c54/87c54-20 programming algorithm refer to table 3 and figures 11 and 14 for address, data, and control signals set up. to program the 87c54 the following sequence must be exercised. 1. input the valid address on the address lines. 2. input the appropriate data byte on the data lines. 3. activate the correct combination of control sig- nals. 4. raise ea /v pp from v cc to 12.75v g 0.25v. 5. pulse ale/prog 5 times for the eprom ar- ray, and 25 times for the encryption table and the lock bits. repeat 1 through 5 changing the address and data for the entire array or until the end of the object file is reached. program verify program verify may be done after each byte or block of bytes is programmed. in either case a complete verify of programmed array will ensure reliable pro- gramming of the 87c54. the lock bits cannot be directly verified. verification of the lock bits is done by observing that their fea- tures are enabled. refer to the eprom program lock section in this data sheet. 270849 25 5 pulses figure 14. programming signal's waveforms 17
automotive 87c54/87c54-20 eprom program lock the 87c54 program lock system, when pro- grammed, protect the onboard program against soft- ware piracy. the 87c54 has a 3-level program lock system and a 64-byte encryption array. since this is an eprom device, all locations are user programmable. see table 4. program lock bits the 87c54 has 3 programmable lock bits that when programmed according to table 4 will provide differ- ent levels of protection for the on-chip code and data. see table 3. erasing the eprom also erases the encryption ar- ray and the program lock bits, returning the part to full functionality. encryption array within the eprom array are 64 bytes of encryption array that are initially unprogrammed (all 1's). every time that a byte is addressed during a verify, 6 ad- dress lines are used to select a byte of the encryp- tion array. this byte is then exclusive-nor'ed (xnor) with the code byte, creating an encryption verify byte. the algorithm, with the array in the un- programmed state (all 1's), will return the code in it's original, unmodified form. for programming the en- cryption array, refer to table 3 (eprom program- ming modes). reading the signature bytes the 87c54 has 3 signature bytes in locations 30h, 31h and 60h. to read these bytes follow the proce- dure for eprom verify, but activate the control lines provided in table 3 for read signature byte. location contents 87c54 30h 89h 31h 58h 60h 54h table 4. program lock bits and the features program lock bits protection type lb1 lb2 lb3 1 u u u no program lock features enabled. (code verify will still be encrypted by the encryption array if programmed.) 2 p u u movc instructions executed from external program memory are disabled from fetching code bytes from internal memory, ea is sampled and latched on reset, and further programming of the eprom is disabled. 3 p p u same as 2, also verify is disabled. 4 p p p same as 3, also external execution is disabled. any other combination of the lock bits is not defined. 18
automotive 87c54/87c54-20 eprom programming and verification characteristics (t a e 21 cto27 c; v cc e 5v g 20%; v ss e 0v) advanced informationecontact intel for design-in information symbol parameter min max units v pp programming supply voltage 12.5 13.0 v i pp programming supply current 75 ma 1/t clcl oscillator frequency 4 6 mhz t avgl address setup to prog low 48t clcl t ghax address hold after prog 48t clcl t dvgl data setup to prog low 48t clcl t ghdx data hold after prog 48t clcl t ehsh (enable) high to v pp 48t clcl t shgl v pp setup to prog low 10 m s t ghsl v pp hold after prog 10 m s t glgh prog width 90 110 m s t avqv address to data valid 48t clcl t elqv enable low to data valid 48t clcl t ehqz data float after enable 0 48t clcl t ghgl prog high to prog low 10 m s eprom programming and verification waveforms 270849 26 19
automotive 87c54/87c54-20 data sheet revision history the following are key differences between this data sheet and the -003 version of the data sheet. 1. the data sheet has been revised to include the 20 mhz 87c54. the title was changed from 87c54 to 87c54/87c54-20. 2. rst pin in figure 3 has been changed to reset pin. 3. max i cc has been corrected to reflect test program conditions. 4. figure 6, i cc vs. frequency, has been changed to reflect new i cc specifications. 5. 87c54-20 a.c. timings have been added to the external memory characteristics table. the following are key differences between this data sheet and the -002 version of the data sheet. 1. ``nc'' pin labels changed to ``reserved'' in figure 3. 2. capacitor value for ceramic resonators deleted in figure 4. 3. replaced a0 a15 with p1.0 p1.7, p2.0 p2.5 (eprom programming and verification waveforms). 4. replaced d0 d7 with p0 (eprom programming and verification waveforms). the following are the key differences between the -001 and the -002 versions of this data sheet. 1. the rst description has been modified to clarify the reset operation when the oscillator is not running. 2. figure 4 (oscillator connections) has been changed for ceramic resonators. 3. a description of rfi reduction mode has been added. 4. v il ,i il ,i tl and i cc dc characteristics have been revised. 5. ac and dc characteristics are specified to g 10% v cc revised from g 20% v cc . 20

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