W83877TF/W83877TG
-86 -
The corresponding power-on setting pin is NRTSA (pin 36).
PNP REGISTER PNPCVS = 1 PNPCVS = 0
CR20 FCH 00H
CR23 DEH 00H
CR24 FEH 00H
CR25 BEH 00H
CR26 23H 00H
CR27 05H 00H
CR28 43H 00H
CR29 60H 00H
Note: The new value of PNPCVS must be complementary to the old one to make an effective change. For example, the user
must set PNPCVS to 1 first and then reset it to 0 to reset these PnP registers if the present value of PNPCVS is 0.
Bit 1: Reserved.
HEFRAS (Bit 0): combines with HEFERE (bit 5 of CR0C) to define how to access Extended Function
Registers (refer to bit 5 of CR0C description). The corresponding power-on setting
pin is NDTRA (pin 35).
11.2.23 Configuration Register 17 (CR17), default = 00H
When the device is in Extended Function mode and EFIR is 17H, the CR17 register can be accessed
through EFDR. The bit definitions are as follows:
1
2
34567
0
DSUBLGRQ
DSUALGRQ
DSPRLGRQ
DSFDLGRQ
PRIRQOD
reserved
reserved
reserved
Bit 7-bit 5: Reserved.
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.
