W83977ATF Datasheet, PDF (140/207 Pages) Winbond – WINBOND I/O

W83977ATF
PRELIMINARY
11.3 Logical Device 1 (Parallel Port)
CR30 (Default 0x01 if PNPCSV = 0 during POR, default 0x00 otherwise)
Bit 7 - 1: Reserved.
Bit 0:
= 1 Activates the logical device.
= 0 Logical device is inactive.
CR60, CR 61 (Default 0x03, 0x78 if PNPCSV = 0 during POR, default 0x00, 0x00 otherwise)
These two registers select Parallel Port I/O base address.
[0x100:0xFFC] on 4 byte boundary (EPP not supported) or
[0x100:0xFF8] on 8 byte boundary (all modes supported, EPP is only available when the base
address is on 8 byte boundary).
CR70 (Default 0x07 if PNPCSV = 0 during POR, default 0x00 otherwise)
Bit 7 - 4: Reserved.
Bit [3:0]: These bits select IRQ resource for Parallel Port.
CR74 (Default 0x04)
Bit 7 - 3: Reserved.
Bit 2 - 0: These bits select DRQ resource for Parallel Port.
0x00=DMA0
0x01=DMA1
0x02=DMA2
0x03=DMA3
0x04 - 0x07= No DMA active
CRF0 (Default 0x3F)
Bit 7: PP Interrupt Type:
Not valid when the parallel port is in the printer Mode (100) or the standard & Bi-directional
Mode (000).
= 1 Pulsed Low, released to high-Z .
= 0 IRQ follows nACK when parallel port in EPP Mode or [Printer, SPP, EPP] under ECP.
Bit [6:3]: ECP FIFO Threshold.
Bit 2 - 0 Parallel Port Mode
= 100 Printer Mode (Default)
= 000 Standard and Bi-direction (SPP) mode
= 001 EPP - 1.9 and SPP mode
= 101 EPP - 1.7 and SPP mode
= 010 ECP mode
= 011 ECP and EPP - 1.9 mode
= 111 ECP and EPP - 1.7 mode.
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Publication Release Date:April 1998
Revision 0.52