EM78P257
OTP ROM
In a similar way, if the Comparator Status Changed Interrupt is used to wake-up the EM78P257A/B , the following
instructions must be executed before SLEP:
MOV A, @0bxx000110
CONTW
; Select internal TCC clock
CLR R1
MOV A, @0bxxxx1110
CONTW
; Clear TCC and prescaler
; Select WDT prescaler
WDTC
MOV A, @0b0xxxxxxx
IOW RE
; Clear WDT and prescaler
; Disable WDT
MOV A, @0b1111xxxx
IOW RF
; Enable comparator high interrupt
ENI (or DISI)
SLEP
; Enable (or disable) global interrupt
; Sleep
NOP
One problem user must be aware of, is that after waking up from the sleep mode, WDT will enable automatically.
The WDT operation (being enabled or disabled) should be handled appropriately by software after waking up from
the sleep mode.
Table 6 Summary of the Initialized Values for Registers
Address Name
Reset Type
Bit Name
Bit 7
C57
1
Bit 6
C76
1
Bit 5
C55
1
Bit 4
C54
1
Bit 3
C53
1
Bit 2
C52
1
Bit 1
C51
1
Bit 0
C50
1
Power-On
N/A
N/A
N/A
N/A
IOC50
IOC60
IOC70
/RESET and WDT
1
1
1
1
1
1
1
1
Wake-Up from Pin
Change
P
P
P
P
P
P
P
P
Bit Name
C67
1
C66
1
C65
1
C64
1
C63
1
C62
1
C61
1
C60
1
Power-On
/RESET and WDT
1
1
1
1
1
1
1
1
Wake-Up from Pin
Change
P
P
P
P
P
P
P
P
Bit Name
X
1
1
X
1
1
X
1
1
X
1
1
X
1
1
X
1
1
C71
1
C70
1
Power-On
/RESET and WDT
1
1
Wake-Up from Pin
Change
P
P
P
P
P
P
P
P
Bit Name
TCC2E TCC4E TCC6E TCCBE
X
0
0
X
0
0
X
0
0
X
0
0
Power-On
0
0
0
0
0
0
0
0
IOC80
(TCCCR)
/RESET and WDT
Wake-Up from Pin
Change
P
P
P
P
P
P
P
P
Bit Name
COIE4 COIE3 COIE2 COIE1
CE4
CE3
CE2
CE1
Power-On
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
IOC90
(CMPCR)
N/A
N/A
/RESET and WDT
Wake-Up from Pin
Change
P
P
P
P
P
P
P
P
IOCA0
(COICS)
Bit Name
X
1
1
X
1
1
X
1
1
X
1
1
CI3
0
CI2
0
CI1
0
CI0
0
Power-On
/RESET and WDT
0
0
0
0
This specification is subject to change without prior notice.
34
07.27.2004 (V1.4)
ELAN [ ELAN MICROELECTRONICS CORP ]
