Datasheet

i
4127H–8051–02/08
A/T89C51AC2
Table of Contents
Features................................................................................................. 1
Description............................................................................................ 1
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