
PRELIMINARY W79E225A/227A DATA SHEET
8-bit Microcontroller
Publication Release Date: December 14, 2007
- 1 -
Revision A2.0
Table of Contents-
1.
2.
3.
GENERAL DESCRIPTION ......................................................................................................... 5
FEATURES................................................................................................................................. 6
PARTS INFORMATION LIST ..................................................................................................... 7
3.1
Lead Free (RoHS) Parts information list......................................................................... 7
PIN CONFIGURATION............................................................................................................... 8
PIN DESCRIPTION................................................................................................................... 10
5.1
Port 4 ............................................................................................................................ 12
MEMORY ORGANIZATION...................................................................................................... 13
6.1
Program Memory (on-chip Flash)................................................................................. 13
6.2
Data Memory ................................................................................................................13
6.3
Auxiliary SRAM............................................................................................................. 14
6.4
NVM Data Flash Memory ............................................................................................. 14
6.4.1
Operation........................................................................................................................19
SPECIAL FUNCTION REGISTERS ......................................................................................... 21
INSTRUCTION SET.................................................................................................................. 74
8.1
Instruction Timing.......................................................................................................... 82
8.1.1
External Data Memory Access Timing............................................................................84
POWER MANAGEMENT.......................................................................................................... 87
9.1
Idle Mode...................................................................................................................... 87
9.2
Power Down Mode ....................................................................................................... 87
RESET CONDITIONS............................................................................................................... 89
10.1
Sources of reset............................................................................................................ 89
10.1.1
External Reset..............................................................................................................89
10.1.2
Power-On Reset (POR)................................................................................................89
10.1.3
Watchdog Timer Reset.................................................................................................89
10.2
Reset State................................................................................................................... 90
INTERRUPTS ........................................................................................................................... 91
11.1
Interrupt Sources .......................................................................................................... 91
11.2
Priority Level Structure ................................................................................................. 91
11.2.1
Response Time ............................................................................................................95
PROGRAMMABLE TIMERS/COUNTERS ............................................................................... 96
12.1
Timer/Counters 0 & 1....................................................................................................96
12.1.1
Time-Base Selection ....................................................................................................96
12.1.2
Mode 0 .........................................................................................................................96
12.1.3
Mode 1 .........................................................................................................................97
12.1.4
Mode 2 .........................................................................................................................97
12.1.5
Mode 3 .........................................................................................................................98
4.
5.
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9.
10.
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12.