User`s guide

Table C–4 (Cont.) PC87312 Combination Controller Register Address Space

Map

Address Offset

Read/Write

Physical

Address Register

Diskette Registers

3F0-R 1 C000 7E00 Status A register

3F1-R 1 C000 7E20 Status B register

3F2-R/W 1 C000 7E40 Digital output register

3F3-R/W 1 C000 7E60 Tape drive register

3F4-R 1 C000 7E80 Main status register

3F4-W 1 C000 7E80 Data rate select register

3F5-R/W 1 C000 7EA0 Data (FIFO) register

3F6 1 C000 7EC0 None (tristate bus)

3F7-R 1 C000 7EE0 Digital input register

3F7-W 1 C000 7EE0 Conﬁguration control register

COM1 Serial Port Registers

3F8-R 0DLAB=0 1 C000 7F00 COM1 receiver buffer register

3F8-W 0DLAB=0 1 C000 7F00 COM1 transmitter holding register

3F8 0DLAB=1 1 C000 7F00 COM1 divisor latch register (LSB)

3F9 1DLAB=0 1 C000 7F20 COM1 interrupt enable register

3F9 1DLAB=1 1 C000 7F20 COM1 divisor latch register (MSB)

3FA-R 1 C000 7F40 COM1 interrupt identiﬁcation register

3FA-W 1 C000 7F40 COM1 FIFO control register

3FB 1 C000 7F60 COM1 line control register

3FC 1 C000 7F80 COM1 modem control register

3FD 1 C000 7FA0 COM1 line status register

3FE 1 C000 7FC0 COM1 modem status register

3FF 1 C000 7FE0 COM1 scratch pad register

(continued on next page)

PCI Address Maps C–9