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EM78P447N
8-Bit Microcontroller with OTP ROM
18 •
Product Specification (V1.1) 03.30.2005
(This specification is subject to change without further notice)
(A) Any of the wake-up pins is “0” as illustrated in Figure. 5. Upon waking, the controller
will continue to execute the succeeding address. Under this case, before entering
SLEEP2 MODE, the wake-up function of the trigger sources (P60~P67 and
P74~P75) should be selected (e.g., input pin) and enabled (e.g., pull-high, wake-up
control). It should be noted that after waking up, the WDT is enabled if the Code
Option bit ENWDT is “0”. The WDT operation (to be enabled or disabled) should be
appropriately controlled by software after waking up.
(B) WDT time-out (if enabled) or external reset input on /RESET pin will trigger a
controller reset.
Table 6 Usage of Sleep1 and Sleep2 Mode
Usage of Sleep1 and Sleep2 Mode
SLEEP2 SLEEP1
(a) Before SLEEP (a) Before SLEEP
1. Set Port6 or P74 or P75 Input 1. Execute SLEP instruction
2. Enable Pull-High and set WDT
prescaler over 1:1 (Set CONT.7 and
CONT.3 ~ CONT.0)
3. Enable Wake-up (Set IOCB or IOCE.0)
4. Execute Seep2 (Set IOCE.4)
(b) After Wake-up (b) After Wake-up
1. Next instruction 1. Reset
2. Disable Wake-up
3. Disable WDT (Set IOCE.5)
If Port6 Input Status Changed Wake-up is used to wake-up the EM78P447S (Case [a]
above), the following instructions must be executed before entering SLEEP2 mode:
MOV A, @11111111b ; Set Port6 input
IOW R6
MOV A, @0xxx1010b
; Set Port6 pull-high, WDT prescaler,
prescaler must set over 1:1
CONTW
MOV A, @00000000b ; Enable Port6 wake-up function
IOW RB
MOV A, @xx00xxx1b ; Enable SLEEP2
IOW RE
After
Wake-up
NOP
MOV A, @11111111b ; Disable Port6 wake-up function
IOW RB
MOV A, @ xx01xxx1b ; Disable WDT
IOW RE