com20020-5 Standard Microsystems Corp., com20020-5 Datasheet - Page 5

• Manufacturer Part Number: com20020-5
• Description: Com20020-5 Ulanc Universal Local Area Network Controller With 2k X 8 On-board Ram
• Manufacturer: Standard Microsystems Corp.

19
20
21
16,15
17
18
DIP PIN
NO.
23
24
25
19,18
20
21
PLCC PIN
NO.
nReset in
nInterrupt
nChip Select nCS
nPulse 2,
nPulse 1
Receive In
nTransmit
nEnable
NAME
DESCRIPTION OF PIN FUNCTIONS
TRANSMISSION MEDIA INTERFACE
nRESET IN
nINTR
nPULSE2,
nPULSE1
RXIN
nTXEN
SYMBOL
5
Input. This active low signal issued by the
microcontroller executes a hardware reset.
It is used to activate the internal reset
circuitry within the COM20020-5.
Output. This active low signal is generated
by the COM20020-5 when an enabled
interrupt condition occurs. nINTR returns to
its inactive state when the interrupt status
condition or the corresponding interrupt
mask bit is reset.
Input. This active low signal issued by the
microcontroller selects the COM20020-5 for
an access.
Output. In Normal Mode, these active low
signals carry the transmit data information,
encoded
COM20020-5 to the media driver circuitry.
When the device is in Backplane Mode, the
nPULSE1 signal driver is programmable
(push/pull
nPULSE2 signal provides a clock with
frequency
connected to a weak internal pull-up resistor
in backplane mode.
Input. This signal carries the receive data
information from the line receiver circuitry to
the COM20020-5.
Output. This signal is used in Backplane
Mode
transmission. The polarity of the signal is
programmable by grounding the nPULSE2
pin. This option is valid only in Backplane
Mode.
to
in
of
enable
or
DESCRIPTION
pulse
crystal/4.
open-drain),
the
format,
line
nPULSE1
drivers
while
from
the
the
for
is