W83877TF Datasheet, PDF (149/154 Pages) Winbond – I/O chip disk drive adapter

W83877TF
8.4.12 Power Management 1 Timer 4 (PM1TMR4)
Register Location:
<CR33>+BH System I/O Space
Default Value:
00h
Attribute:
Read only
Size:
8 bits
765
43
21
0
Bit
Name
0-7 Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Description
Reserved. These bits always return a value of zero.
8.4.13 General Purpose Event 0 Status Register 1 (GP0STS1)
Register Location:
<CR34> System I/O Space
Default Value:
00h
Attribute:
Read/write
Size:
8 bits
765
43
21
0
URBSCISTS
URASCISTS
FDCSCISTS
PRTSCISTS
Reserved
Reserved
Reserved
Reserved
These bits indicate the status of the SCI input, which is set when the device's IRQ is raised. If the
corresponding enable bit in the SCI interrupt enable register (in GP0EN1) is set, an SCI interrupt is
raised and routed to the output pin. Writing a 1 clears the bit, and writing a 0 has no effect. If the bit
is not cleared, new IRQ for the SCI logic input is ignored, therefore no SCI interrupt is raised.
Bit
Name
Description
0
URBSCISTS UART B SCI status, which is set by the UART B IRQ.
1
URASCISTS UART A SCI status, which is set by the UART A IRQ.
2
FDCSCISTS FDC SCI status, which is set by the FDC IRQ.
3
PRTSCISTS PRT SCI status, which is set by the printer port IRQ.
4-7 Reserved
Reserved.
- 123 -
Publication Release Date: March 1998
Version 0.61