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Revision 1.1
G
Core Logic Module
(Continued)
Index B9h
PIC Shadow Register (RO)
Reset Value: xxh
7:0
PIC Shadow.
This 8-bit port sequences through the following list of shadowed Interrupt Controller registers. At power on, a
pointer starts at the first register in the list and continuing through the other registers in subsequent reads according to the
read sequence. A write to this register resets the read sequence to the first register. Each shadow register in the sequence
contains the last data written to that location.
The read sequence for this register is:
1. PIC1 ICW1
2. PIC1 ICW2
3. PIC1 ICW3
4. PIC1 ICW4 - Bits [7:5] of ICW4 are always 0.
5. PIC1 OCW2 - Bits [6:3] of OCW2 are always 0 (See Note).
6. PIC1 OCW3 - Bits [7:4] are 0 and bits [6:3] are 1.
7. PIC2 ICW1
8. PIC2 ICW2
9. PIC2 ICW3
10. PIC2 ICW4 - Bits [7:5] of ICW4 are always 0.
11. PIC2 OCW2 - Bits [6:3] of OCW2 are always 0 (See Note).
12. PIC2 OCW3 - Bits [7:4] are 0 and bits [6:3] are 1.
Note:
To restore OCW2 to the shadow register value, write the appropriate address twice. First with the shadow register
value, then with the shadow register value ORed with C0h.
Index BAh
PIT Shadow Register (RO)
Reset Value: xxh
7:0
PIT Shadow.
This 8-bit port sequences through the following list of shadowed Programmable Interval Timer registers. At
power on, a pointer starts at the first register in the list continuing through the other registers in subsequent reads according
to the read sequence. A write to this register resets the read sequence to the first register. Each shadow register in the
sequence contains the last data written to that location.
The read sequence for this register is:
1. Counter 0 LSB (least significant byte)
2. Counter 0 MSB
3. Counter 1 LSB
4. Counter 1 MSB
5. Counter 2 LSB
6. Counter 2 MSB
7. Counter 0 Command Word
8. Counter 1 Command Word
9. Counter 2 Command Word
Note:
The LSB/MSB of the count is the Counter base value, not the current value.
Bits [7:6] of the command words are not used.
Index BBh
RTC Index Shadow Register (RO)
Reset Value: xxh
7:0
RTC Index Shadow.
The RTC Shadow register contains the last written value of the RTC Index register (I/O Port 070h).
Index BCh
Clock Stop Control Register (R/W)
Reset Value: 00h
7:4
PLL Delay.
The programmed value in this field sets the delay (in milliseconds) after a break event occurs before the internal
SUSP# signal is deasserted to the GX1 module. This delay is designed to allow the clock chip and CPU PLL to stabilize
before starting execution. This delay is only invoked if the STP_CLK bit was set.
The 4-bit field allows values from 0 to 15 msec.
0000: 0 msec
0100: 4 msec
1000: 8 msec
0001: 1 msec
0101: 5 msec
1001: 9 msec
0010: 2 msec
0110: 6 msec
1010: 10 msec
0011: 3 msec
0111: 7 msec
1011: 11 msec
Reserved.
Set to 0.
CPU Clock Stop.
0: Normal internal SUSP#/SUSPA# handshake.
1: Full system Suspend.
1100: 12 msec
1101: 13 msec
1110: 14 msec
1111: 15 msec
3:1
0
Table 5-29. F0: PCI Header and Bridge Configuration Registers for GPIO and LPC Support (Continued)
Bit
Description