SMC Networks SMC91C95 Uživatelský manuál stáhnout pdf (Strana 89)

802Ah - Modem I/O BASE Register 0

7 6 5 4 3 2 1 0

A7 A6 A5 A4 A3 0 0 0

0 0 0 0 0 0 0 0

802Ch - Modem I/O BASE Register 1

7 6 5 4 3 2 1 0

A15 A14 A13 A12 A11 A10 A9 A8

0 0 0 0 0 0 1 1

The Modem I/O Base registers determine the

base address of the I/O range used to access

function specific registers. These registers allow

the function's registers to be placed anywhere in

the host's I/O space. I/O Base 0 contains the

low order byte (A7-A0) and I/O Base 1 contains

the high order byte (A15-A8). Since the modem

function requires 8 I/O locations, bits 2-0 of I/O

Base 0 are always 0. Since only A15 to A4 are

decoded by the controller (64K address space),

it is up to the host to resolve any conflicts with

addressing above 64K.

These registers are still accessable even if the

“Enable Base and Limit” bit in the MCOR is

cleared (0).

1 2 ... 84 85 86 87 88 89 90 91 92 93 94 ... 138 139

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SMC Networks SMC91C95 Uživatelský manuál Strana 89