AMD SC2200 manual RTC Registers, RTC Register Map, Index Type Name, Vpp Pur

SuperI/O Module 32580B

5.5.3RTC Registers

The RTC registers can be accessed (see Section 5.4.2.1 "LDN 00h - Real-Time Clock" on page 104) at any time dur- ing normal operation mode (i.e.,when VSB is within the rec- ommended operation range). This access is disabled during battery-backed operation. The write operation to

these registers is also disabled if bit 7 of the CRD Register is 0.

Note: Before attempting to perform any start-up proce- dures, read about bit 7 (VRT) of the CRD Register.

This section describes the RTC Timing and Control Regis- ters that control basic RTC functionality.

Table 5-19. RTC Register Map

			Reset
Index	Type	Name	Type
00h	R/W	SEC. Seconds Register	VPP PUR
01h	R/W	SECA. Seconds Alarm Register	VPP PUR
02h	R/W	MIN. Minutes Register	VPP PUR
03h	R/W	MINA. Minutes Alarm Register	VPP PUR
04h	R/W	HOR. Hours Register	VPP PUR
05h	R/W	HORA. Hours Alarm Register	VPP PUR
06h	R/W	DOW. Day Of Week Register	VPP PUR
07h	R/W	DOM. Date Of Month Register	VPP PUR
08h	R/W	MON. Month Register	VPP PUR
09h	R/W	YER. Year Register	VPP PUR
0Ah	R/W	CRA. RTC Control Register A	Bit specific
0Bh	R/W	CRB. RTC Control Register B	Bit specific
0Ch	RO	CRC. RTC Control Register C	Bit specific
0Dh	RO	CRD. RTC Control Register D	VPP PUR
Programmable1	R/W	DOMA. Date of Month Alarm Register	VPP PUR
Programmable1	R/W	MONA. Month Alarm Register	VPP PUR
Programmable1	R/W	CEN. Century Register	VPP PUR

1.Overlaid on RAM bytes in range 0Eh-7Fh. See Section 5.4.2.1 "LDN 00h - Real-Time Clock" on page 104.

Table 5-20. RTC Registers

Bit	Description
Index 00h	Seconds Register - SEC (R/W)	Reset Type: VPP PUR
7:0	Seconds Data. Values may be 00 to 59 in BCD format or 00 to 3B in binary format.
Index 01h	Seconds Alarm Register - SECA (R/W)	Reset Type: VPP PUR
7:0	Seconds Alarm Data. Values may be 00 to 59 in BCD format or 00 to 3B in binary format.
	When bits 7 and 6 are both set to one (“11”), unconditional match is selected.
Index 02h	Minutes Register - MIN (R/W)	Reset Type: VPP PUR
7:0	Minutes Data. Values can be 00 to 59 in BCD format, or 00 to 3B in binary format.
Index 03h	Minutes Alarm Register - MINA (R/W)	Reset Type: VPP PUR
7:0	Minutes Alarm Data. Values can be 00 to 59 in BCD format, or 00 to 3B in binary format.
	When bits 7 and 6 are both set to 1, unconditional match is selected. See Section 5.5.2.5 "Alarms" on page 113 for more
	information about “unconditional” matches.
AMD Geode™ SC2200 Processor Data Book		117