em78p156n ELAN Microelectronics Corp, em78p156n Datasheet - Page 21

• Manufacturer Part Number: em78p156n
• Description: 8-bit Micro-controller
• Manufacturer: ELAN Microelectronics Corp

vector following wake-up. If ENI is executed before SLEP, the instruction will begin to execute from the address
008H after wake-up. If DISI is executed before SLEP, the operation will restart from the succeeding instruction
right next to SLEP after wake-up.
Only one of Cases 2 and 3 can be enabled before entering the sleep mode. That is,
If Port 6 Input Status Change Interrupt is used to wake-up the EM78P156N (Case [a] above), the following
instructions must be executed before SLEP:
One problem user should be aware of, is that after waking up from the sleep mode, WDT would enable
automatically. The WDT operation (being enabled or disabled) should be handled appropriately by software
after waking up from the sleep mode.
This specification is subject to change without prior notice.
[a] if Port 6 Input Status Change Interrupt is enabled before SLEP , WDT must be disabled. by
[b] if WDT is enabled before SLEP, Port 6 Input Status Change Interrupt must be disabled. Hence,
MOV A, @xx000110b
CONTW
CLR R1
MOV A, @xxxx1110b
CONTW
WDTC
MOV A, @0xxxxxxxb
IOW RE
MOV R6, R6
MOV A, @00000x1xb
IOW RF
ENI (or DISI)
SLEP
NOP
software. However, the WDT bit in the option register remains enabled. Hence, the
EM78P156N can be awakened only by Case 1 or 3.
the EM78P156N can be awakened only by Case 1 or 2. Refer to the section on Interrupt.
; Clear TCC and prescaler
; Clear WDT and prescaler
; Read Port 6
; Enable Port 6 input change interrupt
; Enable (or disable) global interrupt
; Sleep
; Select internal TCC clock
; Select WDT prescaler
; Disable WDT
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EM78P156N
OTP ROM
07.29.2004 (V1.2)