NEC PD754144 - Manual (Page 226)

CHAPTER 8 STANDBY FUNCTION
226 User’s Manual U10676EJ3V0UM
BTAND4: SKTCLR IRQ0 ; INT0 = 1?
BR VSUBBT ; NO
SKT PORT6.1 ; P61 = 1?
BR PDOWN ; Power down
SET1 BTM.3 ; Starts BT
WAIT: SKT IRQBT ; Waits for 175 ms
BR WAIT
SKT PORT6.1
BR PDOWN
MOV A, #0011B ; High-speed mode
MOV PCC, A
[EI IEn] ; IEn ← 1
RETI
PDOWN: MOV A, #0 ; Lowest-speed mode
MOV PCC, A
[DI IEn] ; IEn ← 0
Keeps 46 machine cycles
SETHLT: HALT ; HALT mode
NOP
RETI
VSUBBT: CLR1 IRQBT
Processing during intermittent operation
BR SETHLT
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