SMC Networks SMC91C95 - Manual (Page 9)

9
DESCRIPTION OF PIN FUNCTIONS
PIN NO. NAME SYMBOL TYPE DESCRIPTION
113 nROM/
nPCMCIA
I/O4 with
pullup
This pin is sampled at the end of RESET.
When this pin is sampled low the SMC91C95
is configured for PCMCIA operation and all
pin definitions correspond to the PCMCIA
mode. For ISA operation this pin is left open
and is used as a ROM chip select output that
goes active when nMEMR is low and the
address bus contains a valid ROM address.
35, 36,
38-43,
45-50,
52, 53
Address 0-
15 A0-A15 I Input address lines 0 through 15.
54 Address 16 A16 I ISA - Input address line 16.
nFlash
Memory
Write nFWE O4 PCMCIA - Output. Flash Memory Write
Enable used for programming the attribute
memory. Goes active (low) when nWE=0 and
WRATTRIB=1 (in ECOR bit 3).
55 Address 17 A17 I ISA - Input address line 17.
nFlash
Memory
Chip Select nFCS O4 PCMCIA - Output. Flash Memory Chip Select
used to access attribute memory. Goes active
(low) when nREG=0, nCE1=0 and A15=0.
56 Address 18 A18 I Input address line 18.
57 Address 19 A19 I with pullup ISA - Input address line 19.
Card Enable
1 nCE1 PCMCIA - Card Enable 1 input. Used to
select card on even byte accesses.
34 Address
Enable AEN I with pullup ISA - Address enable input. Used as an
address qualifier. Address decoding is only
enabled when AEN is low.
nREG PCMCIA - Attribute memory and IO select
input. Asserted when the card attribute space
or IO space is being accessed.