em78f644nso28s ELAN Microelectronics Corp, em78f644nso28s Datasheet - Page 106

• Manufacturer Part Number: em78f644nso28s
• Description: Flash Series 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

EM78F648/644/642/641/548/544/542/541N
8-Bit Microcontroller
96 •
2
Software disables WDT (watchdog timer) but hardware must be enabled before applying Port 6 Change
Wake-Up function (CODE Option Register and Bit 11 (ENWDTB-) set to “1”).
I. Wake-up from Port 6 Input Status Change
a) Before SLEEP
b) After WAKE-UP
1. Disable WDT
2. Read I/O Port 6 (MOV R6,R6)
3. Enable interrupt: After wake-up, if “ENI,”
4. Enable wake-up enable bit
5. Execute "SLEP" instruction
1. If "ENI"
2. If "DISI"
switch to interrupt vector (006H). If “DISI,”
execute the next instruction.
Disable interrupt: Always execute the next
instruction.
6.5.2 I/O for EM78F648/548N
The I/O registers, Port 5~Port 9 are bi-directional tri-state I/O ports. All have high
sink/drive setting by software. Port 5, Port 6, and Port 7 also feature Wake up
function. Furthermore, Port 6 is also equipped with input status change interrupt
function. Each I/O pin can be defined as "input" or "output" pin by the I/O control
register (IOC5 ~ IOC9).
The I/O registers and I/O control registers are both readable and writable.
Table below shows the usage of EM78F64xN/54xN Port 6 Input Change Wake-
up/Interrupt functions:
Interrupt vector (006H)
Next instruction
2
Usage of Port 6 input status changed Wake-up/Interrupt
(execute very carefully)
(This specification is subject to change without further notice)
II Port 6 Input Status Change Interrupt
1. Read I/O Port 6 (MOV R6,R6)
2. Execute "ENI"
3. Enable interrupt
4. IF Port 6 change (interrupt) → Interrupt vector
(006H)
Product Specification (V1.0) 05.05.2010