EM78P447S
OTP ROM
(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 4 Usage of Sleep1 and Sleep2 Mode
Usage of Sleep1 and Sleep2 Mode
SLEEP2
SLEEP1
(a) Before SLEEP
(a) Before SLEEP
1. Execute SLEP instruction
1. Set Port6 or P74 or P75 Input
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. Reset
1. Next instruction
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
RE
IOW
After Wake-up
NOP
MOV
A, @11111111b ; Disable Port6 wake-up function
IOW
RB
MOV
A, @ xx01xxx1b ; Disable WDT
RE
IOW
Note:
After waking up from the SLEEP2 mode, WDT is automatically enabled. The WDT enabled/disabled
operation after waking up from SLEEP2 mode should be appropriately defined in the software.
To avoid reset from occurring when the port6 status changed interrupt enters into interrupt vector or
is used to wake-up the MCU, the WDT prescaler must be set above 1:1 ratio.
This specification is subject to change without prior notice.
19
06.25.2003 (V1.1)
ELAN [ ELAN MICROELECTRONICS CORP ]
