SMC91C100 Datasheet, PDF (7/83 Pages) List of Unclassifed Manufacturers – FEAST Fast Ethernet Controller

PIN NO.
NAME
42,
40-38,
36-33, 59,56,
49-47,
45-43,
69-67, 65,64,
62-60,
81-76, 71,70
RAM Data
Bus
84,87,
88,90,
91,96,
99,101,
100,98,
89,92,
103,102,
104
RAM
Address
Bus
97
31,57,
73,86
93
3
4
nReceive
DMA
Crystal 1
Crystal 2
5,10,
23,27,
41,63,
74,83,
85,107,
119,125,
132,143,
165,179,
186,191
Power
DESCRIPTION OF PIN FUNCTIONS
BUFFER
SYMBOL
TYPE
DESCRIPTION
RD0-RD31
I/O4P
Bidirectional. Carries the local buffer memory
read and write data. Reads are always 32 bits
wide. Writes are controlled individually at the
byte level.
RA2-RA16
O4
Outputs. This bus specifies the buffer RAM
doubleword being accessed by the
SMC91C100.
nROE
nRW E0-
RW E3
nRCVDMA
XTAL1
XTAL2
VDD
O4
Output. Used to read a doubleword from
buffer RAM.
O4
Outputs. Used to write any byte, word or
dword in RAM.
O4
Output. This pin is active during SMC91C100
write memory cycles of receive packets.
I_CLK
An external 25 MHz crystal is connected across
these pins. If a TTL clock is supplied instead,
it should be connected to XTAL1 and XTAL2
should be left open.
+5V power supply pins.
7