AT89C4051技术资料,AT89C4051规格书,datasheet.pdf

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1、FeaturesCompatible with MCS51 Products4K Bytes of Reprogrammable Flash Memory Endurance:1,000 Write/Erase Cycles2.7V to 6V Operating RangeFully Static Operation:0 Hz to 24 MHzTwo-level Program Memory Lock128 x 8-bit Internal RAM15 Programmable I/O LinesTwo 16-bit Timer/CountersSix Interrupt SourcesP

2、rogrammable Serial UART ChannelDirect LED Drive OutputsOn-chip Analog ComparatorLow-power Idle and Power-down ModesBrown-out DetectionPower-On Reset(POR)Green(Pb/Halide-free/RoHS Compliant)Packaging 1.DescriptionThe AT89C4051 is a low-voltage,high-performance CMOS 8-bit microcontroller with 4K bytes

3、 of Flash programmable and erasable read-only memory.The device is man-ufactured using Atmels high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set.By combining a versa-tile 8-bit CPU with Flash on a monolithic chip,the Atmel AT89C4051 is a po

4、werful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications.The AT89C4051 provides the following standard features:4K bytes of Flash,128 bytes of RAM,15 I/O lines,two 16-bit timer/counters,a five-vector,two-level inter-rupt architecture,a

5、 full duplex serial port,a precision analog comparator,on-chip oscillator and clock circuitry.In addition,the AT89C4051 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/

6、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.8-bit Microcontroller with 4K Bytes FlashAT89C4051 1001EMICRO6/05深圳市万瑞尔科技有限公司 专业电子元件供应商 0755-282697

7、89 http:/ 21001EMICRO6/05AT89C4051 2.Pin Configuration2.1PDIP/SOIC3.Block Diagram1234567891020191817161514131211RST/VPP(RXD)P3.0(TXD)P3.1XTAL2XTAL1(INT0)P3.2(INT1)P3.3(TO)P3.4(T1)P3.5GNDVCCP1.7P1.6P1.5P1.4P1.3P1.2P1.1(AIN1)P1.0(AIN0)P3.7 31001EMICRO6/05 AT89C40514.Pin Description4.1VCCSupply voltage

8、.4.2GNDGround.4.3Port 1Port 1 is an 8-bit bi-directional I/O port.Port pins P1.2 to P1.7 provide internal pullups.P1.0 and P1.1 require external pullups.P1.0 and P1.1 also serve as the positive input(AIN0)and the neg-ative input(AIN1),respectively,of the on-chip precision analog comparator.The Port

9、1 output buffers can sink 20 mA and can drive LED displays directly.When 1s are written to Port 1 pins,they can be used as inputs.When pins P1.2 to P1.7 are used as inputs and are externally pulled low,they will source current(IIL)because of the internal pullups.Port 1 also receives code data during

10、 Flash programming and verification.4.4Port 3Port 3 pins P3.0 to P3.5,P3.7 are seven bi-directional I/O pins with internal pullups.P3.6 is hard-wired as an input to the output of the on-chip comparator and is not accessible as a gen-eral-purpose I/O pin.The Port 3 output buffers can sink 20 mA.When

11、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 AT89C4051 as listed below

12、:Port 3 also receives some control signals for Flash programming and verification.4.5RSTReset input.All I/O pins are reset to 1s as soon as RST goes high.Holding the RST pin high for two machine cycles while the oscillator is running resets the device.Each machine cycle takes 12 oscillator or clock

13、cycles.4.6XTAL1Input to the inverting oscillator amplifier and input to the internal clock operating circuit.Port PinAlternate FunctionsP3.0RXD(serial input port)P3.1TXD(serial output port)P3.2INT0(external interrupt 0)P3.3INT1(external interrupt 1)P3.4T0(timer 0 external input)P3.5T1(timer 1 extern

14、al input)41001EMICRO6/05AT89C4051 4.7XTAL2Output from the inverting oscillator amplifier.5.Oscillator CharacteristicsXTAL1 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 5-1.Either a quartz crystal

15、 or ceramic resonator may be used.To drive the device from an external clock source,XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 5-2.There are no require-ments on the duty cycle of the external clock signal,since the input to the internal clocking circuitry is through a

16、divide-by-two flip-flop,but minimum and maximum voltage high and low time specifications must be observed.Figure 5-1.Oscillator ConnectionsNote:C1,C2=30 pF 10 pF for Crystals =40 pF 10 pF for Ceramic ResonatorsFigure 5-2.External Clock Drive Configuration 51001EMICRO6/05 AT89C40516.Special Function

17、RegistersA map of the on-chip memory area called the Special Function Register(SFR)space is shown in the Table 6-1.Note that not all of the addresses are occupied,and unoccupied addresses may not be imple-mented on the chip.Read accesses to these addresses will in general return random data,and writ

18、e accesses will have an indeterminate effect.User software should not write 1s to these unlisted locations,since they may be used in future products to invoke new features.In that case,the reset or inactive values of the new bits will always be 0.Table 6-1.AT89C4051 SFR Map and Reset Values0F8H0FFH0

19、F0HB000000000F7H0E8H0EFH0E0HACC000000000E7H0D8H0DFH0D0HPSW000000000D7H0C8H 0CFH0C0H0C7H0B8HIPXXX000000BFH0B0HP3111111110B7H0A8HIE0XX000000AFH0A0H 0A7H98HSCON00000000SBUFXXXXXXXX9FH90HP11111111197H88HTCON00000000TMOD00000000TL000000000TL100000000TH000000000TH1000000008FH80HSP00000111DPL00000000DPH000

20、00000PCON0XXX000087H 61001EMICRO6/05AT89C4051 7.Restrictions on Certain InstructionsThe AT89C4051 is an economical and cost-effective member of Atmels growing family of micro-controllers.It contains 4K bytes of Flash program memory.It is fully compatible with the MCS-51 architecture,and can be progr

21、ammed using the MCS-51 instruction set.However,there are a few considerations one must keep in mind when utilizing certain instructions to program this device.All the instructions related to jumping or branching should be restricted such that the destination address falls within the physical program

22、 memory space of the device,which is 4K for the AT89C4051.This should be the responsibility of the software programmer.For example,LJMP 0FE0H would be a valid instruction for the AT89C4051(with 4K of memory),whereas LJMP 1000H would not.7.1Branching InstructionsLCALL,LJMP,ACALL,AJMP,SJMP,JMP A+DPTR.

23、These unconditional branching instruc-tions will execute correctly as long as the programmer keeps in mind that the destination branching address must fall within the physical boundaries of the program memory size(loca-tions 00H to FFFH for the 89C4051).Violating the physical space limits may cause

24、unknown program behavior.CJNE.,DJNZ.,JB,JNB,JC,JNC,JBC,JZ,JNZ.With these conditional branching instructions the same rule above applies.Again,violating the memory boundaries may cause erratic execution.For applications involving interrupts,the normal interrupt service routine address locations of th

25、e 80C51 family architecture have been preserved.7.2MOVX-related Instructions,Data MemoryThe AT89C4051 contains 128 bytes of internal data memory.Thus,in the AT89C4051 the stack depth is limited to 128 bytes,the amount of available RAM.External DATA memory access is not supported in this device,nor i

26、s external Program memory execution.Therefore,no MOVX.instructions should be included in the program.A typical 80C51 assembler will still assemble instructions,even if they are written in violation of the restrictions mentioned above.It is the responsibility of the controller user to know the physi-

27、cal features and limitations of the device being used and adjust the instructions used correspondingly.8.Program Memory Lock BitsOn the chip are two lock bits which can be left unprogrammed(U)or can be programmed(P)to obtain the additional features listed in the Table 8-1.Note:1.The Lock Bits can on

28、ly be erased with the Chip Erase operation.Table 8-1.Lock Bit Protection Modes(1)Program Lock BitsProtection TypeLB1LB21UUNo program lock features2PUFurther programming of the Flash is disabled3PPSame as mode 2,also verify is disabled 71001EMICRO6/05 AT89C40519.Idle ModeIn idle mode,the CPU puts its

29、elf to sleep while all the on-chip peripherals remain active.The mode is invoked by software.The content of the on-chip RAM and all the special functions regis-ters remain unchanged during this mode.The idle mode can be terminated by any enabled interrupt or by a hardware reset.P1.0 and P1.1 should

30、be set to“0”if no external pullups are used,or set to“1”if external pullups are used.It should be noted that when idle is terminated by a hardware 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-

31、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

32、or to external memory.10.Power-down ModeIn 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 Registers retain their val-ues until the power-down mode is terminated.The only exit from power-d

33、own 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.P1.0 and P1.1 should be set to“0”if no exte

34、rnal pullups are used,or set to“1”if external pullups are used.11.Brown-out DetectionWhen VCC drops below the detection threshold,all port pins(except P1.0 and P1.1)are weakly pulled high.When VCC goes back up again,an internal Reset is automatically generated after a delay of typically 15 msec.The

35、nominal brown-out detection threshold is 2.1V 10%.VCCCC2.1V2.1VPORT PININTERNAL RESET15 msec.81001EMICRO6/05AT89C4051 12.Programming The FlashThe AT89C4051 is shipped with the 4K bytes of on-chip PEROM code memory array in the erased state(i.e.,contents=FFH)and ready to be programmed.The code memory

36、 array is pro-grammed one byte at a time.Once the array is programmed,to re-program any non-blank byte,the entire memory array needs to be erased electrically.Internal Address Counter:The AT89C4051 contains an internal PEROM address counter which is always reset to 000H on the rising edge of RST and

37、 is advanced by applying a positive going pulse to pin XTAL1.Programming Algorithm:To program the AT89C4051,the following sequence is recommended.1.Power-up sequence:Apply power between VCC and GND pins Set RST and XTAL1 to GND2.Set pin RST to“H”Set pin P3.2 to“H”3.Apply the appropriate combination

38、of“H”or“L”logic levels to pins P3.3,P3.4,P3.5,P3.7 to select one of the programming operations shown in the PEROM Programming Modes table.To Program and Verify the Array:4.Apply data for Code byte at location 000H to P1.0 to P1.7.5.Raise RST to 12V to enable programming.6.Pulse P3.2 once to program

39、a byte in the PEROM array or the lock bits.The byte-write cycle is self-timed and typically takes 1.2 ms.7.To verify the programmed data,lower RST from 12V to logic“H”level and set pins P3.3 to P3.7 to the appropriate levels.Output data can be read at the port P1 pins.8.To program a byte at the next

40、 address location,pulse XTAL1 pin once to advance the internal address counter.Apply new data to the port P1 pins.9.Repeat steps 6 through 8,changing data and advancing the address counter for the entire 4K bytes array or until the end of the object file is reached.10.Power-off sequence:set XTAL1 to

41、“L”set RST to“L”Turn VCC power offData Polling:The AT89C4051 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 writ-ten data on P1.7.Once the write cycle has been completed,true data is vali

42、d 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.Pin P3.1 is pulled low after P3.2 goes High during programming to indicate BUSY.P3.1 is

43、pulled High again when programming is done to indicate READY.91001EMICRO6/05 AT89C4051Program Verify:If lock bits LB1 and LB2 have not been programmed code data can be read back via the data lines for verification:1.Reset the internal address counter to 000H by bringing RST from“L”to“H”.2.Apply the

44、appropriate control signals for Read Code data and read the output data at the port P1 pins.3.Pulse pin XTAL1 once to advance the internal address counter.4.Read the next code data byte at the port P1 pins.5.Repeat steps 3 and 4 until the entire array is read.The lock bits cannot be verified directl

45、y.Verification of the lock bits is achieved by observing that their features are enabled.Chip Erase:The entire PEROM array(4K bytes)and the two Lock Bits are erased electrically by using the proper combination of control signals and by holding P3.2 low for 10 ms.The code array is written with all“1”

46、s in the Chip Erase operation and must be executed before any non-blank memory byte can be re-programmed.Reading the Signature Bytes:The signature bytes are read by the same procedure as a nor-mal verification of locations 000H,001H,and 002H,except that P3.5 and P3.7 must be pulled to a logic low.Th

47、e values returned are as follows.(000H)=1EH indicates manufactured by Atmel(001H)=41H indicates AT89C405113.Programming InterfaceEvery 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 s

48、elf-timed and once initiated,will automatically time itself to completion.Most major worldwide programming vendors offer support for the Atmel AT89 microcontroller series.Please contact your local programming vendor for the appropriate software revision.Notes:1.The internal PEROM address counter is

49、reset to 000H on the rising edge of RST and is advanced by a positive pulse at XTAL1 pin.2.Chip Erase requires a 10-ms PROG pulse.3.P3.1 is pulled Low during programming to indicate RDY/BSY.13.1Flash Programming ModesModeRST/VPPP3.2/PROGP3.3P3.4P3.5P3.7Write Code Data(1)(3)12VLHHHRead Code Data(1)HH

50、LLHHWrite Lock Bit-112VHHHHBit-212VHHLLChip Erase12VHLLLRead Signature ByteHHLLLL(2)101001EMICRO6/05AT89C4051 Figure 13-1.Programming the Flash MemoryFigure 13-2.Verifying the Flash MemoryPPAT89C4051P3.1RDY/BSYAT89C4051 111001EMICRO6/05 AT89C4051Note:1.Only used in 12-volt programming mode.15.Flash