Intel® 460GX Chipset Software Developer’s Manual
15-15
PCI/LPC Bridge Description
The extended RAM bank is also accessed using an indexed scheme. I/O address 72h is used as the
address pointer and I/O address 73h is used as the data register. Index addresses above 127h are not
valid.
15.5.1.1
Register A
Address Offset:
0Ah
Default Value:
NA - This register is not affected by any system reset signal.
Attribute:
Read/Write
This register is used for general configuration of the RTC Functions.
Bit(s)
Description
7
UPDATE IN PROGRESS (UIP): This bit may be monitored as a status flag. When asserted as a 1,
the update is soon to occur or is in progress. If 0, the update cycle will not start for at least 244 µs.
The time, calendar, and alarm information in RAM is always available when the UIP bit is 0.
6:4
Division Chain Select (DVx): These three bits control the divider chain for the oscillator.
DV2 DV1 DV0 Function
0 1 0 Normal Operation
1 1 X Divider Reset
1 0 1 Bypass 15 stages (test mode only)
1 0 0 Bypass 10 stages (test mode only)
0 1 1 Bypass 5 stages (test mode only)
0 1 1 Invalid
0 0 0 Invalid
3:0
Rate Select Bits (RSx): Selects one of 13 taps of the 15 stage divider chain. The selected tap can
generate a periodic interrupt if the PIE bit is set in register B. Otherwise this tap will set the PF flag
of register C. If the periodic interrupt is not to be used, these bits should all be set to zero.
RS3
RS2
RS1
RS0
Periodic Rate
0
0
0
0
Interrupt never toggles
0
0
0
1
3.90625 ms
0
0
1
0
7.8125 ms
0
0
1
1
122.070
µ
s
0
1
0
0
244.141
µ
s
0
1
0
1
488.281
µ
s
0
1
1
0
976.5625
µ
s
0
1
1
1
1.953125 ms
1
0
0
0
3.90625 ms
1
0
0
1
7.8125 ms
1
0
1
0
15.625 ms
1
0
1
1
31.25 ms
1
1
0
0
62.5 ms
1
1
0
1
125 ms
1
1
1
0
250 ms
1
1
1
1
500 ms
Содержание 460GX
Страница 1: ...Intel 460GX Chipset System Software Developer s Manual June 2001 Document Number 248704 001 ...
Страница 20: ...Introduction 1 8 Intel 460GX Chipset Software Developer s Manual ...
Страница 80: ...System Architecture 3 8 Intel 460GX Chipset Software Developer s Manual ...
Страница 90: ...System Address Map 4 10 Intel 460GX Chipset Software Developer s Manual ...
Страница 98: ...Memory Subsystem 5 8 Intel 460GX Chipset Software Developer s Manual ...
Страница 146: ...AGP Subsystem 7 16 Intel 460GX Chipset Software Developer s Manual ...
Страница 170: ...IFB Register Mapping 9 6 Intel 460GX Chipset Software Developer s Manual ...
Страница 190: ...IFB Usage Considerations 10 20 Intel 460GX Chipset Software Developer s Manual ...
Страница 232: ...LPC FWH Interface Configuration 11 42 Intel 460GX Chipset Software Developer s Manual ...
Страница 244: ...IDE Configuration 12 12 Intel 460GX Chipset Software Developer s Manual ...
Страница 258: ...Universal Serial Bus USB Configuration 13 14 Intel 460GX Chipset Software Developer s Manual ...
Страница 270: ...SM Bus Controller Configuration 14 12 Intel 460GX Chipset Software Developer s Manual ...
Страница 288: ...PCI LPC Bridge Description 15 18 Intel 460GX Chipset Software Developer s Manual ...
Страница 294: ...IFB Power Management 16 6 Intel 460GX Chipset Software Developer s Manual ...