W83877ATF Datasheet, PDF (128/191 Pages) Winbond – enhanced version from Winbonds most popular I/O chip W83877F

W83877ATF
PRIRQOD (Bit 4):
0
printer IRQ ports are totem-poles in SPP mode and open-drains in ECP/EPP mode.
1
printer IRQ ports are totem-poles in all modes.
DSFDLGRQ (Bit 3):
0
enable FDC legacy mode on IRQ and DRQ selections. DO register bit 3 has effect on
selecting IRQ.
1
disable FDC legacy mode on IRQ and DRQ selections. DO register bit 3 has no effect
on selecting IRQ.
DSPRLGRQ (Bit 2):
0
enable PRT legacy mode on IRQ and DRQ selections. DCR bit 4 has effect on
selecting IRQ.
1
disable PRT legacy mode on IRQ and DRQ selections. DCR bit 4 has no effect on
selecting IRQ.
DSUALGRQ (Bit 1):
0
enable UART A legacy mode on IRQ selection. MCR bit 3 has effect on selecting IRQ.
1
disable UART A legacy mode on IRQ selection. MCR bit 3 has no effect on selecting
IRQ.
DSUBLGRQ (Bit 0):
0
enable UART B legacy mode on IRQ selection. MCR bit 3 has effect on selecting IRQ.
1
disable UART B legacy mode on IRQ selection. MCR bit 3 has no effect on selecting
IRQ.
8.2.24 Configuration Register 18 (CR18), default=00H
When the device is in Extended Function mode and EFIR is 18H, the CR18 register can be accessed
through EFDR. The bit definitions are as follows:
765
43
21
0
SHARA
SHARB
SHARC
SHARD
SHARE
SHARF
SHARG
SHARH
This register is used to select whether these interrupt request pins are in the IRQ sharing mode. While
in the IRQ sharing mode, the corresponding pin is low active for 200ns for the interrupt request and
keeps tri-stated otherwise.
- 124 -
Publication Release Date: April 1998
Version 0.51