AT89C51ED2-RDTIM datasheet(135/137 Pages) ATMEL

135 / 137 page

AT89C51RD2/ED2

4235E–8051–04/04

Serial I/O Port ...................................................................................... 49

Framing Error Detection ..................................................................................... 49

Automatic Address Recognition.......................................................................... 50

Registers............................................................................................................. 52

Baud Rate Selection for UART for Mode 1 and 3............................................... 52

UART Registers.................................................................................................. 55

Keyboard Interface ............................................................................. 60

Registers............................................................................................................. 61

Serial Port Interface (SPI) ................................................................... 64

Features.............................................................................................................. 64

Signal Description............................................................................................... 64

Functional Description ........................................................................................ 66

Interrupt System ................................................................................. 73

Registers............................................................................................................. 74

Interrupt Sources and Vector Addresses............................................................ 75

Power Management ............................................................................ 82

Introduction ......................................................................................................... 82

Idle Mode ............................................................................................................ 82

Power-Down Mode ............................................................................................. 82

Registers............................................................................................................. 85

Hardware Watchdog Timer ................................................................ 86

Using the WDT ................................................................................................... 86

WDT during Power-down and Idle...................................................................... 87

ONCE® Mode (ON- Chip Emulation) .................................................. 88

Power-off Flag ..................................................................................... 89

Reduced EMI Mode ............................................................................. 90

EEPROM Data Memory ....................................................................... 91

Write Data........................................................................................................... 91

Read Data........................................................................................................... 93

Registers............................................................................................................. 94

Flash/EEPROM Memory ..................................................................... 95

Features.............................................................................................................. 95

Flash Programming and Erasure ........................................................................ 95

Flash Registers and Memory Map...................................................................... 96

Flash Memory Status.......................................................................................... 99

Memory Organization ......................................................................................... 99

AT89C51ED2-RDTIM Datasheet(PDF) 135 Page - ATMEL Corporation