PCMCIA CONFIGURATION REGISTERS DESCRIPTION

Ethernet Function (Base Address 8000h)

8000h - Ethernet Configuration Option Register (ECOR)

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

SRESET

LevIREQ

 

 

WRATTRI

Enable

Enable

Enable

 

 

 

 

B

IREQ

Base and

Function

 

 

 

 

 

 

Limit

 

 

 

 

 

 

 

 

 

0

1

0

0

0

0

0

0

 

 

 

 

 

 

 

 

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.

82

Page 82
Image 82
SMC Networks SMC91C95 manual Pcmcia Configuration Registers Description, Sreset, Wrattri, Ireq