SMC Networks SMC91C95 User Manual
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Modem Function (Base Address 8020h)
8020h - Modem Configuration Option Register (MCOR)
7
6
5
4
3
2
1
0
SRESET
LevIREQ
Enable
IREQ
Enable
Base and
Limit
Enable
Function
0
1
0
0
0
0
0
0
BIT 7 - SRESET: This bit when set clears all
internal registers associated with the Modem
function (except itself) and asserts the
nMRESET pin .
BIT 6 - LevIREQ: This bit is read only and reads
as a one to indicate level mode interrupts are
used. Pulse mode interrupts are not supported.
BIT 5 - Not defined
BIT 4 - Not defined
BIT 3 - Not defined
BIT 2 - Enable IREQ Routing: This bit enables
(1) or disables (0) the Modem function from
asserting nIREQ.
BIT 1 - Enable Base and Limit: This bit enables
the on board modem I/O base decoder. If set,
the on-board decoder is used to select the
function. If cleared, the decoder is disabled and
it is assumed that the host provides for the
decoding. When the decode is disabled, the
function is enabled, and is configured for 16 bits
(and not in power-down mode), the signal -
IOIs16 is always asserted. For multifunction
PCMCIA functionality, this bit must be set.
BIT 0 - Enable Function: This bit enables (1) or
disables (0) the Modem function. While the
Modem is disabled the SMC91C95 inhibits
nMCS, IREQ is not generated for the Modem
function and nINPACK is not returned for
accesses to the Modem registers.