GM82C803CN Datasheet, PDF (12/84 Pages) List of Unclassifed Manufacturers – 2.88 MB FDC/ Dual UARTs with FIFO/PIO(EPP/ ECP)/ IDE Interface/ S-IR/ PnP

GM82C803CN
3.1.10 DMA Selection Register (DSR)
Index = C9
Bit 7 Bit 6 Bit 5 Bit 4
0000
0001
0010
0011
FDC DMA
None
DMA_A
DMA_B
DMA_C
Bit 3 Bit 2 Bit 1 Bit 0
0000
0001
0010
0011
Parallel DMA
None
DMA_A
DMA_B
DMA_C
This register is used to select the DMA for the FDC (bits 7:4) and the parallel port (bits 3:0).
Any unselected DMA ACK output is in tristate.
3.1.11 IRQ Selection Register (IRR)
Index = CA
Bit 7 Bit 6 Bit 5 Bit 4
0000
0001
0010
0011
0100
0101
0110
0111
1000
FDC IRQ
None
IRQ_A
IRQ_B
IRQ_C
IRQ_D
IRQ_E
IRQ_F
None
IRQ_H
Bit 3 Bit 2 Bit 1 Bit 0
0000
0001
0010
0011
0100
0101
0110
0111
1000
Parallel IRQ
None
IRQ_A
IRQ_B
IRQ_C
IRQ_D
IRQ_E
IRQ_F
None
IRQ_H
This register is used to select the IRQ for the FDC (bits 7:4) and the parallel port (bits 3:0).
Any unselected IRQ output (registers : IRR, SIR, IIR) is in tristate.
3.1.12 Serial IRQ selection Register (SIR)
Index = CB
Bit 7 Bit 6 Bit 5 Bit 4
0000
0001
0010
0011
0100
0101
0110
0111
1000
Serial 1 IRQ
None
IRQ_A
IRQ_B
IRQ_C
IRQ_D
IRQ_E
IRQ_F
None
IRQ_H
Bit 3 Bit 2 Bit 1 Bit 0
0000
0001
0010
0011
0100
0101
0110
0111
1000
Serial 2 IRQ
None
IRQ_A
IRQ_B
IRQ_C
IRQ_D
IRQ_E
IRQ_F
None
IRQ_H
This register is used to select the IRQ for serial port 1 (bits 7:4) and the serial port 2 (bits 3:0).
Any unselected IRQ output (registers : IRR, SIR, IIR) is in tristate.