Oki MSM80C154S, MSM83C154S manual Power control register Pcon, Interrupt signal, CPU is reset

MSM80C154S/83C154S							¡ Semiconductor
Power control register (PCON)
NAME	ADDRESS	MSB							LSB
		7	6	5	4	3	2	1	0
PCON	87H	SMOD	HPD	RPD	—	GF1	GF0	PD	IDL
BIT LOCATION	FLAG				FUNCTION
PCON.0	IDL	IDLE mode is set when this bit is set to "1". CPU operations are stopped when
		IDLE mode is set, but XTAL1•2, timer/counters 0, 1 and 2, the interrupt circuits,
		and the serial port remain active. IDLE mode is cancelled when the CPU is reset
		or when an interrupt is generated.
PCON.1	PD	PD mode is set when this bit is set to "1". CPU operations and XTAL1•2 are
		stopped when PD mode is set. PD mode is cancelled when the CPU is reset or
		when an interrupt is generated.
PCON.2	GF0	General purpose bit.
PCON.3	GF1	General purpose bit.
PCON.4	—	Reserved bit. The output data is "1", if the bit is read.
PCON.5	RPD	This bit is used to specify cancellation of CPU power down mode (IDLE or PD) by an
		interrupt signal.
		Power-down mode cannot be cancelled by an interrupt signal if the interrupt is not
		enabled by IE (interrupt enable register) when this bit is "0".
		If the interrupt flag is set to "1" by an interrupt request signal when this bit is
		"1" (even if interrupt is disabled), the program is executed from the next address
		of the power-down-mode setting instruction.
		The flag is reset to "0" by software.
PCON.6	HPD	The hard power-down setting mode in enabled when this bit is set to "1".
		If the level of the power failure detect signal applied to the HPDI pin (pin 3.5)
		is changed from "1" to "0" when this bit is "1", XTAL1•2 oscillation is stopped and
		the system is put into hard power down mode. HPD mode is cancelled when the
		CPU is reset.
PCON.7	SMOD	When the timer/counter 1 carry signal is used as a clock in mode 1, 2 or 3 of
		the serial port, this bit has the following functions.
		The serial port operation clock is reduced by 1/2 when the bit is "0" for delayed
		processing. When the bit is "1", the serial port operation clock is normal
		for faster processing.

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