Features • Compatible with MCS-51™ Products • 4K Bytes of In-System Reprogrammable Flash Memory • • • • • • • • – Endurance: 1,000 Write/Erase Cycles Fully Static Operation: 0 Hz to 24 MHz Three-level Program Memory Lock 128 x 8-bit Internal RAM 32 Programmable I/O Lines Two 16-bit Timer/Counters Six Interrupt Sources Programmable Serial Channel Low-power Idle and Power-down Modes Description The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications. P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 RST (RXD) P3.0 (TXD) P3.1 (INT0) P3.2 (INT1) P3.3 (T0) P3.4 (T1) P3.5 (WR) P3.6 (RD) P3.7 XTAL2 XTAL1 GND 44 43 42 41 40 39 38 37 36 35 34 P1.4 P1.3 P1.2 P1.1 (T2 EX) P1.0 (T2) NC VCC P0.0 (AD0) P0.1 (AD1) P0.2 (AD2) P0.3 (AD3) PQFP/TQFP VCC P0.0 (AD0) P0.1 (AD1) P0.2 (AD2) P0.3 (AD3) P0.4 (AD4) P0.5 (AD5) P0.6 (AD6) P0.7 (AD7) EA/VPP ALE/PROG PSEN P2.7 (A15) P2.6 (A14) P2.5 (A13) P2.4 (A12) P2.3 (A11) P2.2 (A10) P2.1 (A9) P2.0 (A8) P1.5 P1.6 P1.7 RST (RXD) P3.0 NC (TXD) P3.1 (INT0) P3.2 (INT1) P3.3 (T0) P3.4 (T1) P3.5 6 5 4 3 2 1 44 43 42 41 40 P1.4 P1.3 P1.2 P1.1 P1.0 NC VCC P0.0 (AD0) P0.1 (AD1) P0.2 (AD2) P0.3 (AD3) PLCC 7 8 9 10 11 12 13 14 15 16 17 39 38 37 36 35 34 33 32 31 30 29 18 19 20 21 22 23 24 25 26 27 28 12 13 14 15 16 17 18 19 20 21 22 PO.4 (AD4) P0.5 (AD5) P0.6 (AD6) P0.7 (AD7) EA/VPP NC ALE/PROG PSEN P2.7 (A15) P2.6 (A14) P2.5 (A13) 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 (WR)P3.6 (RD) P3.7 XTAL2 XTAL1 GND NC (A8) P2.0 (A9) P2.1 (A10) P2.2 (A11) P2.3 (A12) P2.4 33 32 31 30 29 28 27 26 25 24 23 1 2 3 4 5 6 7 8 9 10 11 (WR)P3.6 (RD) P3.7 XTAL2 XTAL1 GND GND (A8) P2.0 (A9) P2.1 (A10) P2.2 (A11) P2.3 (A12) P2.4 P1.5 P1.6 P1.7 RST (RXD) P3.0 NC (TXD) P3.1 (INT0) P3.2 (INT1) P3.3 (T0) P3.4 (T1) P3.5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 AT89C51 Not Recommended for New Designs. Use AT89S51. PDIP Pin Configurations 8-bit Microcontroller with 4K Bytes Flash PO.4 (AD4) P0.5 (AD5) P0.6 (AD6) P0.7 (AD7) EA/VPP NC ALE/PROG PSEN P2.7 (A15) P2.6 (A14) P2.5 (A13) Rev. 0265G–02/00 1 Block Diagram P0.0 - P0.7 P2.0 - P2.7 PORT 0 DRIVERS PORT 2 DRIVERS VCC GND RAM ADDR. REGISTER B REGISTER PORT 0 LATCH RAM PORT 2 LATCH FLASH STACK POINTER ACC BUFFER TMP1 TMP2 PROGRAM ADDRESS REGISTER PC INCREMENTER ALU INTERRUPT, SERIAL PORT, AND TIMER BLOCKS PROGRAM COUNTER PSW PSEN ALE/PROG EA / VPP TIMING AND CONTROL INSTRUCTION REGISTER DPTR RST PORT 1 LATCH PORT 3 LATCH PORT 1 DRIVERS PORT 3 DRIVERS OSC P1.0 - P1.7 2 AT89C51 P3.0 - P3.7 AT89C51 The AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power-down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset. Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pullups. 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 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification. Port 3 Pin Description VCC Supply voltage. GND Ground. Port 3 is an 8-bit bi-directional I/O port with internal pullups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pullups. Port 3 also serves the functions of various special features of the AT89C51 as listed below: Port 0 Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as highimpedance inputs. Port Pin Alternate Functions P3.0 RXD (serial input port) P3.1 TXD (serial output port) Port 0 may also be configured to be the multiplexed loworder address/data bus during accesses to external program and data memory. In this mode P0 has internal pullups. P3.2 INT0 (external interrupt 0) P3.3 INT1 (external interrupt 1) P3.4 T0 (timer 0 external input) Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pullups are required during program verification. P3.5 T1 (timer 1 external input) P3.6 WR (external data memory write strobe) P3.7 RD (external data memory read strobe) Port 1 Port 1 is an 8-bit bi-directional I/O port with internal pullups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups. Port 1 also receives the low-order address bytes during Flash programming and verification. Port 2 Port 2 is an 8-bit bi-directional I/O port with internal pullups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 3 also receives some control signals for Flash programming and verification. RST Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. ALE/PROG Address Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE 3 pulse is skipped during each access to external Data Memory. unconnected while XTAL1 is driven as shown in Figure 2. There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode. Idle Mode PSEN In idle mode, the CPU puts itself to sleep while all the onchip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special functions registers remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset. Program Store Enable is the read strobe to external program memory. When the AT89C51 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. It should be noted that when idle is terminated by a hard ware reset, the device normally resumes program execution, 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 to a port pin 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. EA/VPP External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to V C C for internal program executions. This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming, for parts that require 12-volt VPP. Figure 1. Oscillator Connections C2 XTAL2 XTAL1 Input to the inverting oscillator amplifier and input to the internal clock operating circuit. C1 XTAL1 XTAL2 Output from the inverting oscillator amplifier. GND Oscillator Characteristics XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 1. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left Note: C1, C2 = 30 pF ± 10 pF for Crystals = 40 pF ± 10 pF for Ceramic Resonators Status of External Pins During Idle and Power-down Modes Mode Program Memory ALE PSEN PORT0 PORT1 PORT2 PORT3 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 4 AT89C51 AT89C51 Figure 2. External Clock Drive Configuration ters retain their values until the power-down mode is terminated. The only exit from power-down is a hardware reset. Reset redefines the SFRs but does not change the on-chip RAM. The reset should not be activated before VCC is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize. Program Memory Lock Bits On the chip are three lock bits which can be left unprogrammed (U) or can be programmed (P) to obtain the additional features listed in the table below. Power-down Mode In the power-down mode, the oscillator is stopped, and the instruction that invokes power-down is the last instruction executed. The on-chip RAM and Special Function Regis- When lock bit 1 is programmed, the logic level at the EA pin is sampled and latched during reset. If the device is powered up without a reset, the latch initializes to a random value, and holds that value until reset is activated. It is necessary that the latched value of EA be in agreement with the current logic level at that pin in order for the device to function properly. Lock Bit Protection Modes Program Lock Bits LB1 LB2 LB3 Protection Type 1 U U U No program lock features 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 Flash is disabled 3 P P U Same as mode 2, also verify is disabled 4 P P P Same as mode 3, also external execution is disabled 5 Programming the Flash The AT89C51 is normally shipped with the on-chip Flash memory array in the erased state (that is, contents = FFH) and ready to be programmed. The programming interface accepts either a high-voltage (12-volt) or a low-voltage (V CC ) program enable signal. The low-voltage programming mode provides a convenient way to program the AT89C51 inside the user’s system, while the high-voltage programming mode is compatible with conventional thirdparty Flash or EPROM programmers. The AT89C51 is shipped with either the high-voltage or low-voltage programming mode enabled. The respective top-side marking and device signature codes are listed in the following table. VPP = 12V VPP = 5V Top-side Mark AT89C51 xxxx yyww AT89C51 xxxx-5 yyww Signature (030H) = 1EH (031H) = 51H (032H) =F FH (030H) = 1EH (031H) = 51H (032H) = 05H The AT89C51 code memory array is programmed byte-bybyte in either programming mode. To program any nonblank byte in the on-chip Flash Memory, the entire memory must be erased using the Chip Erase Mode. Programming Algorithm: Before programming the AT89C51, the address, data and control signals should be set up according to the Flash programming mode table and Figure 3 and Figure 4. To program the AT89C51, take the following steps. 1. Input the desired memory location on the address lines. 2. Input the appropriate data byte on the data lines. 3. Activate the correct combination of control signals. 4. Raise EA/VPP to 12V for the high-voltage programming mode. 5. Pulse ALE/PROG once to program a byte in the Flash array or the lock bits. The byte-write cycle is self-timed and typically takes no more than 1.5 ms. Repeat steps 1 through 5, changing the address 6 AT89C51 and data for the entire array or until the end of the object file is reached. Data Polling: The AT89C51 features Data Polling to indicate the end of a write cycle. During a write cycle, an attempted read of the last byte written will result in the complement of the written datum on PO.7. Once the write cycle has been completed, true data are valid on all outputs, and the next cycle may begin. Data Polling may begin any time after a write cycle has been initiated. Ready/Busy: The progress of byte programming can also be monitored by the RDY/BSY output signal. P3.4 is pulled low after ALE goes high during programming to indicate BUSY. P3.4 is pulled high again when programming is done to indicate READY. Program Verify: If lock bits LB1 and LB2 have not been programmed, the programmed code data can be read back via the address and data lines for verification. The lock bits cannot be verified directly. Verification of the lock bits is achieved by observing that their features are enabled. Chip Erase: The entire Flash array is erased electrically by using the proper combination of control signals and by holding ALE/PROG low for 10 ms. The code array is written with all “1”s. The chip erase operation must be executed before the code memory can be re-programmed. Reading the Signature Bytes: The signature bytes are read by the same procedure as a normal verification of locations 030H, 031H, and 032H, except that P3.6 and P3.7 must be pulled to a logic low. The values returned are as follows. (030H) = 1EH indicates manufactured by Atmel (031H) = 51H indicates 89C51 (032H) = FFH indicates 12V programming (032H) = 05H indicates 5V programming Programming Interface Every code byte in the Flash array can be written and the entire array can be erased by using the appropriate combination of control signals. The write operation cycle is selftimed and once initiated, will automatically time itself to completion. All major programming vendors offer worldwide support for the Atmel microcontroller series. Please contact your local programming vendor for the appropriate software revision. AT89C51 Flash Programming Modes RST PSEN EA/VPP P2.6 P2.7 P3.6 P3.7 Write Code Data H L H/12V L H H H Read Code Data H L H L L H H Bit - 1 H L H/12V H H H H Bit - 2 H L H/12V H H L L Bit - 3 H L H/12V H L H L Chip Erase H L H/12V H L L L Read Signature Byte H L H L L L L Mode Write Lock Note: ALE/PROG H (1) H 1. Chip Erase requires a 10 ms PROG pulse. Figure 3. Programming the Flash Figure 4. Verifying the Flash +5V +5V AT89C51 A0 - A7 ADDR. OOOOH/OFFFH A8 - A11 P1 P2.0 - P2.3 AT89C51 VCC P0 PGM DATA A0 - A7 ADDR. OOOOH/0FFFH P2.7 P2.0 - P2.3 P0 P2.6 ALE PROG P3.6 SEE FLASH PROGRAMMING MODES TABLE P2.7 EA VIH/VPP 3-24 MHz PGM DATA (USE 10K PULLUPS) ALE P3.6 VIH P3.7 P3.7 XTAL2 VCC A8 - A11 P2.6 SEE FLASH PROGRAMMING MODES TABLE P1 XTAL2 EA XTAL1 RST 3-24 MHz XTAL1 GND RST PSEN VIH GND VIH PSEN 7 Flash Programming and Verification Waveforms - High-voltage Mode (VPP = 12V) PROGRAMMING ADDRESS P1.0 - P1.7 P2.0 - P2.3 VERIFICATION ADDRESS tAVQV PORT 0 DATA IN tDVGL tAVGL tGHDX DATA OUT tGHAX ALE/PROG tSHGL tGLGH VPP tGHSL LOGIC 1 LOGIC 0 EA/VPP tEHSH tEHQZ tELQV P2.7 (ENABLE) tGHBL P3.4 (RDY/BSY) BUSY READY tWC Flash Programming and Verification Waveforms - Low-voltage Mode (VPP = 5V) PROGRAMMING ADDRESS P1.0 - P1.7 P2.0 - P2.3 VERIFICATION ADDRESS tAVQV PORT 0 DATA IN tDVGL tAVGL tGHDX DATA OUT tGHAX ALE/PROG tSHGL tGLGH LOGIC 1 LOGIC 0 EA/VPP tEHSH tEHQZ tELQV P2.7 (ENABLE) tGHBL P3.4 (RDY/BSY) BUSY tWC 8 AT89C51 READY AT89C51 Flash Programming and Verification Characteristics TA = 0°C to 70°C, VCC = 5.0 ± 10% Symbol VPP (1) Parameter Min Max Units Programming Enable Voltage 11.5 12.5 V 1.0 mA 24 MHz IPP(1) Programming Enable Current 1/tCLCL Oscillator Frequency tAVGL Address Setup to PROG Low 48tCLCL tGHAX Address Hold after PROG 48tCLCL tDVGL Data Setup to PROG Low 48tCLCL tGHDX Data Hold after PROG 48tCLCL tEHSH P2.7 (ENABLE) High to VPP 48tCLCL tSHGL VPP Setup to PROG Low 10 µs tGHSL(1) VPP Hold after PROG 10 µs tGLGH PROG Width tAVQV Address to Data Valid 48tCLCL tELQV ENABLE Low to Data Valid 48tCLCL tEHQZ Data Float after ENABLE tGHBL PROG High to BUSY Low tWC Note: Byte Write Cycle Time 1. Only used in 12-volt programming mode. 3 1 0 110 µs 48tCLCL 1.0 µs 2.0 ms 9 Absolute Maximum Ratings* Operating Temperature.................................. -55°C to +125°C *NOTICE: Storage Temperature ..................................... -65°C to +150°C Voltage on Any Pin with Respect to Ground .....................................-1.0V to +7.0V Maximum Operating Voltage ............................................ 6.6V Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC Output Current...................................................... 15.0 mA DC Characteristics TA = -40°C to 85°C, VCC = 5.0V ± 20% (unless otherwise noted) Symbol Parameter Condition Min Max Units VIL Input Low-voltage (Except EA) -0.5 0.2 VCC - 0.1 V VIL1 Input Low-voltage (EA) -0.5 0.2 VCC - 0.3 V VIH Input High-voltage 0.2 VCC + 0.9 VCC + 0.5 V VIH1 Input High-voltage 0.7 VCC VCC + 0.5 V IOL = 1.6 mA 0.45 V IOL = 3.2 mA 0.45 V VOL Output Low-voltage (Except XTAL1, RST) (XTAL1, RST) (1) (Ports 1,2,3) (1) VOL1 Output Low-voltage (Port 0, ALE, PSEN) VOH Output High-voltage (Ports 1,2,3, ALE, PSEN) IOH = -60 µA, VCC = 5V ± 10% 2.4 V IOH = -25 µA 0.75 VCC V IOH = -10 µA 0.9 VCC V 2.4 V IOH = -300 µA 0.75 VCC V IOH = -80 µA 0.9 VCC V IOH = -800 µA, VCC = 5V ± 10% VOH1 Output High-voltage (Port 0 in External Bus Mode) IIL Logical 0 Input Current (Ports 1,2,3) VIN = 0.45V -50 µA ITL Logical 1 to 0 Transition Current (Ports 1,2,3) VIN = 2V, VCC = 5V ± 10% -650 µA ILI Input Leakage Current (Port 0, EA) 0.45 < VIN < VCC ±10 µA RRST Reset Pull-down Resistor 300 KΩ CIO Pin Capacitance Test Freq. = 1 MHz, TA = 25°C 10 pF Active Mode, 12 MHz 20 mA Idle Mode, 12 MHz 5 mA VCC = 6V 100 µA VCC = 3V 40 µA 50 Power Supply Current ICC Power-down Mode(2) Notes: 10 1. Under steady state (non-transient) conditions, IOL must be externally limited as follows: Maximum IOL per port pin: 10 mA Maximum IOL per 8-bit port: Port 0: 26 mA Ports 1, 2, 3: 15 mA Maximum total IOL for all output pins: 71 mA If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test conditions. 2. Minimum VCC for Power-down is 2V. AT89C51 AT89C51 AC Characteristics Under operating conditions, load capacitance for Port 0, ALE/PROG, and PSEN = 100 pF; load capacitance for all other outputs = 80 pF. External Program and Data Memory Characteristics 12 MHz Oscillator Min Max 16 to 24 MHz Oscillator Symbol Parameter Min Max Units 1/tCLCL Oscillator Frequency 0 24 MHz tLHLL ALE Pulse Width 127 2tCLCL-40 ns tAVLL Address Valid to ALE Low 43 tCLCL-13 ns tLLAX Address Hold after ALE Low 48 tCLCL-20 ns tLLIV ALE Low to Valid Instruction In tLLPL ALE Low to PSEN Low 43 tCLCL-13 ns tPLPH PSEN Pulse Width 205 3tCLCL-20 ns tPLIV PSEN Low to Valid Instruction In tPXIX Input Instruction Hold after PSEN tPXIZ Input Instruction Float after PSEN tPXAV PSEN to Address Valid tAVIV Address to Valid Instruction In 312 5tCLCL-55 ns tPLAZ PSEN Low to Address Float 10 10 ns tRLRH RD Pulse Width 400 6tCLCL-100 ns tWLWH WR Pulse Width 400 6tCLCL-100 ns tRLDV RD Low to Valid Data In tRHDX Data Hold after RD tRHDZ Data Float after RD 97 2tCLCL-28 ns tLLDV ALE Low to Valid Data In 517 8tCLCL-150 ns tAVDV Address to Valid Data In 585 9tCLCL-165 ns tLLWL ALE Low to RD or WR Low 200 3tCLCL+50 ns tAVWL Address to RD or WR Low 203 4tCLCL-75 ns tQVWX Data Valid to WR Transition 23 tCLCL-20 ns tQVWH Data Valid to WR High 433 7tCLCL-120 ns tWHQX Data Hold after WR 33 tCLCL-20 ns tRLAZ RD Low to Address Float tWHLH RD or WR High to ALE High 233 4tCLCL-65 145 0 3tCLCL-45 0 59 75 tCLCL-8 0 5tCLCL-90 3tCLCL-50 0 43 123 tCLCL-20 ns ns 0 300 ns ns tCLCL-10 252 ns ns ns 0 ns tCLCL+25 ns 11 External Program Memory Read Cycle tLHLL ALE tAVLL tLLIV tLLPL tPLIV PSEN tPXAV tPLAZ tPXIZ tLLAX tPXIX A0 - A7 PORT 0 tPLPH INSTR IN A0 - A7 tAVIV PORT 2 A8 - A15 A8 - A15 External Data Memory Read Cycle tLHLL ALE tWHLH PSEN tLLDV tRLRH tLLWL RD tLLAX tAVLL PORT 0 tRLDV tRLAZ A0 - A7 FROM RI OR DPL tRHDZ tRHDX DATA IN A0 - A7 FROM PCL INSTR IN tAVWL tAVDV PORT 2 12 P2.0 - P2.7 OR A8 - A15 FROM DPH AT89C51 A8 - A15 FROM PCH AT89C51 External Data Memory Write Cycle tLHLL ALE tWHLH PSEN tLLWL WR tAVLL tLLAX tQVWX A0 - A7 FROM RI OR DPL PORT 0 tWLWH tQVWH DATA OUT tWHQX A0 - A7 FROM PCL INSTR IN tAVWL PORT 2 P2.0 - P2.7 OR A8 - A15 FROM DPH A8 - A15 FROM PCH External Clock Drive Waveforms tCHCX VCC - 0.5V tCHCX tCLCH tCHCL 0.7 VCC 0.2 VCC - 0.1V 0.45V tCLCX tCLCL External Clock Drive Symbol Parameter 1/tCLCL Oscillator Frequency tCLCL Clock Period tCHCX Min Max Units 0 24 MHz 41.6 ns High Time 15 ns tCLCX Low Time 15 ns tCLCH Rise Time 20 ns tCHCL Fall Time 20 ns 13 Serial Port Timing: Shift Register Mode Test Conditions (VCC = 5.0 V ± 20%; Load Capacitance = 80 pF) 12 MHz Osc Variable Oscillator Max Min Units Symbol Parameter Min Max tXLXL Serial Port Clock Cycle Time 1.0 12tCLCL µs tQVXH Output Data Setup to Clock Rising Edge 700 10tCLCL-133 ns tXHQX Output Data Hold after Clock Rising Edge 50 2tCLCL-117 ns tXHDX Input Data Hold after Clock Rising Edge 0 0 ns tXHDV Clock Rising Edge to Input Data Valid 700 10tCLCL-133 ns Shift Register Mode Timing Waveforms INSTRUCTION ALE 0 1 2 3 4 5 6 7 8 tXLXL CLOCK tQVXH WRITE TO SBUF tXHQX 0 1 tXHDV OUTPUT DATA CLEAR RI VALID 2 3 4 5 6 tXHDX VALID SET TI VALID VALID VALID VALID VALID AC Testing Input/Output Waveforms(1) Note: 14 Float Waveforms(1) V LOAD+ 0.2 VCC + 0.9V TEST POINTS 0.45V VALID SET RI INPUT DATA VCC - 0.5V 7 AT89C51 V LOAD - Note: V OL - 0.1V V OL + 0.1V Timing Reference Points V LOAD 0.2 VCC - 0.1V 1. AC Inputs during testing are driven at VCC - 0.5V for a logic 1 and 0.45V for a logic 0. Timing measurements are made at VIH min. for a logic 1 and VIL max. for a logic 0. 0.1V 0.1V 1. For timing purposes, a port pin is no longer floating when a 100 mV change from load voltage occurs. A port pin begins to float when 100 mV change from the loaded VOH/VOL level occurs. AT89C51 Ordering Information Speed (MHz) Power Supply Ordering Code Package 12 5V ± 20% AT89C51-12AC 44A Commercial AT89C51-12JC 44J (0° C to 70° C) AT89C51-12PC 40P6 AT89C51-12QC 44Q AT89C51-12AI 44A Industrial AT89C51-12JI 44J (-40° C to 85° C) AT89C51-12PI 40P6 AT89C51-12QI 44Q AT89C51-16AC 44A Commercial AT89C51-16JC 44J (0° C to 70° C) AT89C51-16PC 40P6 AT89C51-16QC 44Q AT89C51-16AI 44A Industrial AT89C51-16JI 44J (-40° C to 85° C) AT89C51-16PI 40P6 AT89C51-16QI 44Q AT89C51-20AC 44A Commercial AT89C51-20JC 44J (0° C to 70° C) AT89C51-20PC 40P6 AT89C51-20QC 44Q AT89C51-20AI 44A Industrial AT89C51-20JI 44J (-40° C to 85° C) AT89C51-20PI 40P6 AT89C51-20QI 44Q AT89C51-24AC 44A Commercial AT89C51-24JC 44J (0° C to 70° C) AT89C51-24PC 40P6 AT89C51-24QC 44Q AT89C51-24AI 44A Industrial AT89C51-24JI 44J (-40° C to 85° C) AT89C51-24PI 40P6 AT89C51-24QI 44Q 16 20 24 5V ± 20% 5V ± 20% 5V ± 20% Operation Range Package Type 44A 44-lead, Thin Plastic Gull Wing Quad Flatpack (TQFP) 44J 44-lead, Plastic J-leaded Chip Carrier (PLCC) 40P6 40-lead, 0.600” Wide, Plastic Dual Inline Package (PDIP) 44Q 44-lead, Plastic Gull Wing Quad Flatpack (PQFP) 15 Packaging Information 44A, 44-lead, Thin (1.0 mm) Plastic Gull Wing Quad Flatpack (TQFP) Dimensions in Millimeters and (Inches)* 44J, 44-lead, Plastic J-leaded Chip Carrier (PLCC) Dimensions in Inches and (Millimeters) JEDEC STANDARD MS-018 AC JEDEC STANDARD MS-026 ACB 12.21(0.478) SQ 11.75(0.458) PIN 1 ID 0.45(0.018) 0.30(0.012) 0.80(0.031) BSC .045(1.14) X 45° .045(1.14) X 30° - 45° PIN NO. 1 IDENTIFY .630(16.0) .590(15.0) .656(16.7) SQ .650(16.5) .032(.813) .026(.660) .695(17.7) SQ .685(17.4) .050(1.27) TYP .500(12.7) REF SQ 10.10(0.394) SQ 9.90(0.386) .021(.533) .013(.330) .043(1.09) .020(.508) .120(3.05) .090(2.29) .180(4.57) .165(4.19) 1.20(0.047) MAX 0 7 0.20(.008) 0.09(.003) .012(.305) .008(.203) .022(.559) X 45° MAX (3X) 0.75(0.030) 0.45(0.018) 0.15(0.006) 0.05(0.002) Controlling dimension: millimeters 40P6, 40-lead, 0.600" Wide, Plastic Dual Inline Package (PDIP) Dimensions in Inches and (Millimeters) 2.07(52.6) 2.04(51.8) 44Q, 44-lead, Plastic Quad Flat Package (PQFP) Dimensions in Millimeters and (Inches)* JEDEC STANDARD MS-022 AB 13.45 (0.525) SQ 12.95 (0.506) PIN 1 PIN 1 ID .566(14.4) .530(13.5) 0.50 (0.020) 0.35 (0.014) 0.80 (0.031) BSC .090(2.29) MAX 1.900(48.26) REF .220(5.59) MAX .005(.127) MIN SEATING PLANE .065(1.65) .015(.381) .022(.559) .014(.356) .161(4.09) .125(3.18) .110(2.79) .090(2.29) .012(.305) .008(.203) .065(1.65) .041(1.04) 10.10 (0.394) SQ 9.90 (0.386) .630(16.0) .590(15.0) 2.45 (0.096) MAX 0 REF 15 .690(17.5) .610(15.5) 0.17 (0.007) 0.13 (0.005) 0 7 1.03 (0.041) 0.78 (0.030) Controlling dimension: millimeters 16 AT89C51 0.25 (0.010) MAX Atmel Headquarters Atmel Operations Corporate Headquarters Atmel Colorado Springs 2325 Orchard Parkway San Jose, CA 95131 TEL (408) 441-0311 FAX (408) 487-2600 Europe 1150 E. Cheyenne Mtn. Blvd. Colorado Springs, CO 80906 TEL (719) 576-3300 FAX (719) 540-1759 Atmel Rousset Atmel U.K., Ltd. Coliseum Business Centre Riverside Way Camberley, Surrey GU15 3YL England TEL (44) 1276-686-677 FAX (44) 1276-686-697 Zone Industrielle 13106 Rousset Cedex France TEL (33) 4-4253-6000 FAX (33) 4-4253-6001 Asia Atmel Asia, Ltd. Room 1219 Chinachem Golden Plaza 77 Mody Road Tsimhatsui East Kowloon Hong Kong TEL (852) 2721-9778 FAX (852) 2722-1369 Japan Atmel Japan K.K. 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 Japan TEL (81) 3-3523-3551 FAX (81) 3-3523-7581 Fax-on-Demand North America: 1-(800) 292-8635 International: 1-(408) 441-0732 e-mail [email protected] Web Site http://www.atmel.com BBS 1-(408) 436-4309 © Atmel Corporation 2000. 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