Datasheet

ii
T89C51AC2
4127D–8051–02/03
Registers............................................................................................................. 43
In-System Programming (ISP) ........................................................... 44
Flash Programming and Erasure........................................................................ 44
Boot Process ...................................................................................................... 45
Application Programming Interface..................................................................... 46
XROW Bytes....................................................................................................... 46
Hardware Security Byte...................................................................................... 47
Serial I/O Port ...................................................................................... 48
Framing Error Detection .................................................................................... 48
Automatic Address Recognition.......................................................................... 49
Given Address 50
Broadcast Address ............................................................................................. 50
Registers............................................................................................................. 51
Timers/Counters ................................................................................. 54
Timer/Counter Operations .................................................................................. 54
Timer 0................................................................................................................ 54
Timer 1 57
Interrupt .............................................................................................................. 57
Registers............................................................................................................. 59
Timer 2 ................................................................................................. 63
Auto-Reload Mode............................................................................................. 63
Programmable Clock-Output .............................................................................. 64
Registers............................................................................................................. 65
Watchdog Timer .................................................................................. 68
Watchdog Programming 69
Watchdog Timer During Power-down Mode and Idle 70
Programmable Counter Array (PCA) ................................................ 72
PCA Timer .......................................................................................................... 72
PCA Modules...................................................................................................... 73
PCA Interrupt...................................................................................................... 74
PCA Capture Mode............................................................................................. 74
16-bit Software Timer Mode ............................................................................... 75
High Speed Output Mode 76
Pulse Width Modulator Mode.............................................................................. 76
PCA Watchdog Timer......................................................................................... 77
PCA Registers 78
Analog-to-Digital Converter (ADC) .................................................... 83
Features.............................................................................................................. 83
ADC Port 1 I/O Functions ................................................................................... 83