Datasheet

i
Preliminary/Confidential
T89C51AC2
4127D–8051–02/03
Table of Contents
Features ................................................................................................. 1
Description ............................................................................................ 2
Block Diagram ....................................................................................... 2
Pin Configuration .................................................................................. 3
I/O Configurations................................................................................................. 6
Port 1, Port 3 and Port 4....................................................................................... 6
Port 0 and Port 2................................................................................................... 6
Read-Modify-Write Instructions ............................................................................ 7
Quasi-Bidirectional Port Operation ....................................................................... 8
SFR Mapping ....................................................................................... 10
Clock .................................................................................................... 14
Description.......................................................................................................... 14
Register 17
Power Management ............................................................................ 18
Reset Pin ............................................................................................................ 18
At Power-up (Cold Reset)................................................................................... 18
Reset Recommendation to Prevent Flash Corruption ........................................ 19
Idle Mode............................................................................................................ 19
Power-down Mode.............................................................................................. 20
Registers............................................................................................................. 22
Data Memory ....................................................................................... 23
Internal Space 24
External Space ................................................................................................... 25
Dual Data Pointer 27
Registers............................................................................................................. 28
EEPROM Data Memory ....................................................................... 30
Write Data in the Column Latches...................................................................... 30
Programming ...................................................................................................... 30
Read Data........................................................................................................... 30
Examples............................................................................................................ 31
Registers............................................................................................................. 32
Program/Code Memory ...................................................................... 33
External Code Memory Access 34
Flash Memory Architecture................................................................................. 35
Overview of FM0 Operations.............................................................................. 37