EM78P417N/418N/419N
8-Bit Microprocessor with OTP ROM
6.4.1 Usage of Port 6 Input Change Wake-up/Interrupt Function
(1) Wake-up
(a) Before SLEEP
(2) Wake-up and Interrupt
(a) Before SLEEP
1. Disable WDT
1. Disable WDT
2. Read I/O Port 6 (MOV R6,R6)
3. Execute "ENI" or "DISI"
4. Enable wake-up bit (Set RE ICWE =1)
5. Execute "SLEP" instruction
(b) After wake-up
2. Read I/O Port 6 (MOV R6,R6)
3. Execute "ENI" or "DISI"
4. Enable wake-up bit (Set RE ICWE =1)
5. Enable interrupt (Set IOCF0 ICIE =1)
6. Execute "SLEP" instruction
(b) After wake-up
→ Next instruction
1. IF "ENI" → Interrupt vector (008H)
2. IF "DISI" → Next instruction
(3) Interrupt
(a) Before Port 6 pin change
1. Read I/O Port 6 (MOV R6,R6)
2. Execute "ENI" or "DISI"
3. Enable interrupt (Set IOCF0 ICIE =1)
(b) After Port 6 pin changed (interrupt)
1. IF "ENI" → Interrupt vector (008H)
2. IF "DISI" → Next instruction
6.5 RESET and Wake-up
6.5.1 RESET and Wake-up Operation
A RESET is initiated by one of the following events:
1. Power-on reset
2. /RESET pin input "low"
3. WDT time-out (if enabled).
A device is kept in a RESET condition for the duration of approximately 18ms.2 after the
reset is detected. When in LXT mode, the reset time is 500ms. Once RESET occurs,
the following functions are performed (the initial address is 000h):
ꢀ The oscillator continues running, or will be started (if under sleep mode)
ꢀ The Program Counter (R2) is set to all "0"
ꢀ All I/O port pins are configured as input mode (high-impedance state)
ꢀ The Watchdog Timer and prescaler are cleared
ꢀ When power is switched on, the upper 3 bits of R3 and upper 2 bits of R4 are
cleared
ꢀ The CONT register bits are set to all "1" except for the Bit 6 (INT flag)
2
VDD=5V, WDT Time-out period = 16.5ms ± 30%.
VDD=3V, WDT Time-out period = 18ms ± 30%.
Product Specification (V1.0) 06.23.2005
30 •
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
