SMC Networks SMC91C95 - Manual (Page 14)

14
DESCRIPTION OF PIN FUNCTIONS
PIN NO. NAME SYMBOL TYPE DESCRIPTION
16 n16 Bit
Modem nMIS16 I with pullup Input. When low, it indicates a 16 bit modem,
otherwise the modem is 8 bit wide. Used to
determine if nIOIS16 (PCMCIA) and nIOCS16
(ISA) need to be asserted for modem cycles.
The value of this pin may change from cycle
to cycle.
110 EEPROM
Clock EESK O4 Output. 4
µ
s clock used to shift data in and out
of the serial EEPROM.
109 EEPROM
Chip Select EECS O4 Output. Serial EEPROM chip select.
108 EEPROM
Data Out EEDO/
SDOUT
O4 Output. Connected to the DI input of the serial
EEPROM.
107 EEPROM
Data In EEDI I with pull-
down
Input. Connected to the DO output of the
serial EEPROM.
103,
105, 106
I/O Base IOS0-IOS2 I with pullup Input. External switches can be connected to
these lines to select between predefined
EEPROM configurations. The values of these
pins are readable. These pins are used in ISA
mode only. If in PCMCIA mode, these pins
are not used.
9 nTransmit
LED nTXLED OD16 Internal ENDEC - Transmit LED output.
nTransmit
Enable nTXEN O162 External ENDEC - Active low Transmit
Enable output.
12 nRoard
Select LED nBSELED OD16 Internal ENDEC - Board Select LED activated
by accesses to I/O space (nIORD or nIOWR
active with AEN low and valid address decode
for ISA, and with nREG low and and “Enable
Function” bit in the ECOR register is high for
PCMCIA). The pulse is stretched beyond the
access duration to make the LED visible.
Receive
Data RXD I with pullup External ENDEC - NRZ receive data input.