Datasheet

i
AT89C51ID2
4289C–8051–11/05
Table of Contents
Features................................................................................................. 1
Description............................................................................................ 1
Block Diagram....................................................................................... 3
SFR Mapping......................................................................................... 4
Pin Configurations.............................................................................. 10
Oscillators ........................................................................................... 14
Overview............................................................................................................. 14
Registers............................................................................................................. 14
Functional Block Diagram................................................................................... 17
Operating Modes ................................................................................................ 17
Design Considerations........................................................................................ 19
Timer 0: Clock Inputs.......................................................................................... 20
Enhanced Features............................................................................. 21
X2 Feature.......................................................................................................... 21
Dual Data Pointer Register DPTR...................................................... 25
Expanded RAM (XRAM) ..................................................................... 28
Registers............................................................................................................. 30
Reset.................................................................................................... 31
Introduction......................................................................................................... 31
Reset Input ......................................................................................................... 31
Reset Output....................................................................................................... 32
Power Monitor..................................................................................... 33
Description.......................................................................................................... 33
Timer 2................................................................................................. 35
Auto-Reload Mode.............................................................................................. 35
Programmable Clock-Output .............................................................................. 36
Registers............................................................................................................. 38
Programmable Counter Array PCA................................................... 40
PCA Capture Mode............................................................................................. 48
16-bit Software Timer/ Compare Mode............................................................... 48
High Speed Output Mode ................................................................................... 49
Pulse Width Modulator Mode.............................................................................. 50