DESCRIPTION OF PIN FUNCTIONSOF PIN FUNCTIONSPIN FUNCTIONS
PQFP/TQFP
PIN NO.
BUFFER
TYPE
NAME
nLocal
SYMBOL
DESCRIPTION
108
nLDEV
O16
Output. This active low output is asserted
when AEN is low and A4-A15 decode to the
LAN91C100 address programmed into the
high byte of the Base Address Register.
Device
nLDEV is
a
combinatorial decode of
unlatched address and AEN signals.
177
178
190
nRead
Strobe
nRD
IS
IS
IP
Input.
interfaces.
Used in asynchronous bus
Used in asynchronous bus
nWrite
Strobe
nWR
Input.
interfaces.
nData Path nDATACS
Chip Select
Input. When nDATACS is low, the Data
Path can be accessed regardless of the
values of AEN, A1-A15 and the content of
the BANK SELECT Register. nDATACS
provides an interface for bursting to and
from the LAN91C100 32 bits at a time.
54
55
EEPROM
Clock
EESK
O4
O4
O4
ID
Output. 4 sec clock used to shift data in
and out of the serial EEPROM.
m
EEPROM
Select
EECS
Output. Used for selection and command
framing of the serial EEPROM.
52
EEPROM
Data Out
EEDO
EEDI
Output. Connected to the DI input of the
serial EEPROM.
53
EEPROM
Data In
Input. Connected to the DO output of the
serial EEPROM.
13,15,16
I/O Base
IOS0-IOS2
IP
Input. External switches can be connected
to these lines to select between predefined
EEPROM configurations.
51
Enable
EEPROM
ENEEP
IP
Input. Enables (when high or open)
LAN91C100 accesses to the serial
EEPROM.
Must be grounded if no
EEPROM is connected to the LAN91C100.
6
SMSC [ SMSC CORPORATION ]
