Document
STC89Cxx series MCU STC89LExx series MCU
Data Sheet
CONTENTS
Chapter 1 Introduction......................................................................4 1.1 Features................................................................................................. 4 1.2 Block diagram....................................................................................... 5 1.3 Pin Configurations .............................................................................. 6 1.4 Pin Descriptions.................................................................................... 7 1.5 Pin Package Drawings.......................................................................... 8 Chapter 2 POWER MANAGENMENT, RESET......................... 11 2.1 Power Management ........................................................................... 11
2.1.1 Idle Mode.....................................................................................................11 2.1.2 Power Down (PD) Mode.............................................................................12 2.2 RESET Control................................................................................... 16 2.2.1 Reset pin.......................................................................................................16 2.2.2 Power-On Reset (POR). ..............................................................................17
ited2.2.3 Watch-Dog-Timer.......................................................................................17
2.2.4 Software RESET.........................................................................................20
Lim2.2.5 MAX810 power-on-reset delay..................................................................20
Chapter 3 Memory Organization....................................................21
CU3.1 Program Memory............................................................................... 21
3.2 Data Memory...................................................................................... 22
M3.2.1 On-chip Scratch-Pad RAM........................................................................22
3.2.2 Auxiliary RAM............................................................................................22
STC3.2.3 External RAM.............................................................................................22
3.2.4 Special Function Register for RAM..........................................................23
Chapter 4 Configurable I/O Ports Configurations............................ 29 4.1 Quasi-bidirectional I/O....................................................................... 29 4.2 Push-pull Output................................................................................. 30 4.3 Input-only Mode.................................................................................. 30 4.4 Open-drain Output.............................................................................. 30 Chapter 5 Instruction System..........