目录

功能................................................. ................................................ 1

说明................................................. ........................................... 1

框图................................................ ....................................... 3

SFR映射................................................ ......................................... 4

引脚配置................................................ ................................ 9

端口类型................................................ ........................................... 14

振荡器................................................. ............................................ 15

Registers............................................................................................................. 15

功能框图............................................... .................................... 16

增强功能................................................ ............................. 17

X2功能.......................................................................................................... 17

双数据指针寄存器（ DPTR ） ........................................... ........ 21

扩展存储器（ XRAM ） ............................................. ........................ 24

Registers............................................................................................................. 26

复位................................................. .................................................. 27

介绍......................................................................................................... 27

复位输入......................................................................................................... 27

复位输出.......................................................................................................28

电源监视器................................................ ..................................... 29

Description.......................................................................................................... 29

定时器2 ................................................ ................................................. 31

自动重载模式.............................................. ................................................. 31

可编程

时钟输出................................................................................................................. 32

Registers............................................................................................................. 34

可编程计数器阵列（ PCA ） ............................................ .... 36

PCA捕捉模式............................................... ..............................................

16位软件定时器/比较模式.......................................... .....................

高速输出模式.............................................. .....................................

脉宽调制器方式.............................................. ................................

PCA看门狗定时器............................................... ..........................................

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AT89C51RD2/ED2

4235E–8051–04/04