Datasheet
Table Of Contents
- Features
- Description
- Block Diagram
- SFR Mapping
- Pin Configurations
- Oscillators
- Enhanced Features
- Dual Data Pointer Register DPTR
- Expanded RAM (XRAM)
- Reset
- Power Monitor
- Timer 2
- Programmable Counter Array PCA
- Serial I/O Port
- Interrupt System
- Power Management
- Keyboard Interface
- 2-wire Interface (TWI)
- Serial Port Interface (SPI)
- Hardware Watchdog Timer
- ONCE(TM) Mode (ON Chip Emulation)
- Power-off Flag
- EEPROM Data Memory
- Reduced EMI Mode
- Flash Memory
- Electrical Characteristics
- Absolute Maximum Ratings
- DC Parameters
- AC Parameters
- Explanation of the AC Symbols
- External Program Memory Characteristics
- External Program Memory Read Cycle
- External Data Memory Characteristics
- External Data Memory Write Cycle
- External Data Memory Read Cycle
- Serial Port Timing - Shift Register Mode
- Shift Register Timing Waveforms
- External Clock Drive Waveforms
- AC Testing Input/Output Waveforms
- Float Waveforms
- Clock Waveforms
- Ordering Information
- Packaging Information
- Table of Contents
5
AT89C51ID2
4289C–8051–11/05
Table 2. C51 Core SFRs
MnemonicAddName 76543210
ACC E0h Accumulator
B F0h B Register
PSW D0h Program Status Word CY AC F0 RS1 RS0 OV F1 P
SP 81h Stack Pointer
DPL 82h Data Pointer Low byte
DPH 83h Data Pointer High byte
Table 3. System Management SFRs
MnemonicAddName 76543210
PCON 87h Power Control SMOD1 SMOD0 - POF GF1 GF0 PD IDL
AUXR 8Eh Auxiliary Register 0 - - M0 XRS1 XRS0
EXTRA
M
AO
AUXR1 A2h Auxiliary Register 1 - -
ENBOO
T
-GF30 -DPS
CKRL 97h Clock Reload Register --------
CKSEL 85h Clock Selection Register -------CKS
OSCON86hOscillator Control Register -----SCLKT0OscBEnOscAEn
CKCKON0 8Fh Clock Control Register 0 TWIX2 WDTX2 PCAX2 SIX2 T2X2 T1X2 T0X2 X2
CKCKON1AFhClock Control Register 1 -------SPIX2
Table 4. Interrupt SFRs
MnemonicAddName 76543210
IEN0 A8h Interrupt Enable Control 0 EA EC ET2 ES ET1 EX1 ET0 EX0
IEN1 B1h Interrupt Enable Control 1 -----ESPIETWIEKBD
IPH0 B7h Interrupt Priority Control High 0 - PPCH PT2H PSH PT1H PX1H PT0H PX0H
IPL0 B8h Interrupt Priority Control Low 0 - PPCL PT2L PSL PT1L PX1L PT0L PX0L
IPH1 B3hInterrupt Priority Control High 1-----SPIHIE2CHKBDH
IPL1 B2hInterrupt Priority Control Low 1-----SPILIE2CLKBDL