com90c66 Standard Microsystems Corp., com90c66 Datasheet - Page 6

• Manufacturer Part Number: com90c66
• Description: Arcnet Controller/transceiver With At Interface And On-chip Ram Corporation
• Manufacturer: Standard Microsystems Corp.

PIN NO.
PLCC
56, 55
51-47
46-44
35-42
69
73
57
32
31
nI/O 16-Bit
Chip Select
nSystem Bus
High Enable
nPulse 2,
nPulse 1
Receive In
Memory Base
Address Select
I/O Base
Address Select
Node ID Select NID0-NID7
nTransmit
Activity LED
nBoard Select
Activity LED
NAME
nIOCS16
nSBHE
nPULSE 2,
nPULSE 1
RXIN
MS0-MS4
IOS0-IOS2
nTXLED
nnBSLED
DESCRIPTION OF PIN FUNCTIONS
SYMBOL
TRANSMISSION MEDIA INTERFACE
MISCELLANEOUS
Output. This active low signal is used to indicate that the
present data transfer is a 16-bit I/O cycle. A15-A2 are
used to generate nIOCS16. This is an open-drain signal.
system.
Input.
COM90C66 to transfer data on D8-D15 of the Data Bus.
Output. These active low signals carry the transmit data
information,
COM90C66 to the LAN Driver.
Input. This signal carries the receive data information
from the LAN Driver to the COM90C66.
Input. These signals are generated by external switches.
of memory.
internal pull-up resistors.
Input. These signals are generated by external switches.
I/O locations.
internal pull-up resistors.
Input. These signals are generated by external switches.
this particular COM90C66. These signals are connected
to weak internal pull-up resistors.
Output.
connection to an LED through a resistor to V
transmit activity. This signal has 12mA sink capability.
Output.
connection to an LED through a resistor to V
board activity. This signal has 12mA sink capability.
An external pull-up resistor is typically provided by the
They are used by the memory decoder to select a block
They are used by the I/O decoder to select a block of 16
The Node ID code represents the node identification of
6
This active low signal is used to enable the
This active low signal is used for direct
This active low signal is used for direct
encoded
These signals are connected to weak
These signals are connected to weak
DESCRIPTION
in
pulse
format,
cc
cc
to indicate
to indicate
from
the