SMC Networks SMC91C95 User Manual

Page 82

PCMCIA CONFIGURATION REGISTERS DESCRIPTION

Ethernet Function (Base Address 8000h)

8000h - Ethernet Configuration Option Register (ECOR)

SRESET

LevIREQ

WRATTRI

Enable

IREQ

Enable

Base and

Limit

Enable

Function

BIT 7 - SRESET: This bit when set will clear all
internal registers associated with the Ethernet
function except itself.

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 - WRATTRIB: This bit when when set (1),
allows writting into the external attribute
memory space.

BIT 2 - Enable IREQ Routing: This bit enables
(1) or disables (0) the Ethernet function from
asserting nIREQ. The nIREQ pin on power up
and RESET is in a high (1) de-asserted state.

BIT 1 - Enable Base and Limit: This bit enables
the on board 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. It is then up to the
host to qualify the usage of -IOIs16. For
multifunction PCMCIA functionality, this
bit must be set.

BIT 0 - Enable Function: This bit enables (1) or
disables (0) the Ethernet function. While the
Ethernet function is disabled it remains in
powerdown mode, no access to the Ethernet
I/O space (ie. The bank register are not
accessable) is allowed. IREQ is not generated
for this function and nINPACK is not returned
for accesses to the Ethernet registers.

If the “Magic Packet” function is enabled, the
device is not completly powered down. The
MAC controller is still enabled to receive.