Intel SA-1100 manual Reset Controller Register Locations, Reset Controller Status Register Rcsr

System Control Module

9.6.1.2Reset Controller Status Register (RCSR)

The reset controller reset status register (RCSR) is used by the CPU to determine the last cause or causes of the reset. The SA-1100 has four sources of reset:

•Hardware reset

•Software reset

•Watchdog reset

•Sleep mode reset

Each RCSR status bit is set by a different source of reset, and can be cleared by writing a one back to that bit. Note that the hardware reset state of software, watchdog, and sleep mode reset bits is zero. The table below shows the status bits within RCSR. For reserved bits, writes are ignored and reads return zero.

Bit	31	30		29	28	27	26	25	24	23	22	21	20	19	18	17	16
R/W									Reserved
Reset	0	0		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Bit	15	14		13	12	11	10	9	8	7	6	5	4	3	2	1	0
R/W							Reserved							SMR	WDR	SWR	HWR
Reset	0	0		0	0	0	0	0	0	0	0	0	0	0	0	0	1
Bit	Name									Description
0	HWR		Hardware reset.
			0	– Hardware reset has not occurred since the last time the CPU cleared this bit.
			1	– Hardware reset has occurred since the last time the CPU cleared this bit.
1	SWR		Software reset.
			0	– Software reset has not occurred since the last time the CPU cleared this bit.
			1	– Software reset has occurred since the last time the CPU cleared this bit.
2	WDR		Watchdog reset.
			0	– Watchdog reset has not occurred since the last time the CPU cleared this bit.
			1	– Watchdog reset has occurred since the last time the CPU cleared this bit.
3	SMR		Sleep mode reset.
			0	– Sleep mode reset has not occurred since the last time the CPU cleared this bit.
			1	– Sleep mode reset has occurred since the last time the CPU cleared this bit.
			Note: Each status flag can be cleared only by reading a one and then writing a zero to it.
31..4	—		Reserved.

9.6.2Reset Controller Register Locations

Table 9-5shows the registers associated with the reset controller and the physical addresses used to access them.

Table 9-5.	Reset Controller Register Locations
	Address	Name	Description
	0h 9003 0000	RSRR	Reset controller software reset register
	0h 9003 0004	RCSR	Reset controller status register

SA-1100 Developer’s Manual 9-43