10 Mbps ARCNET (ANSI 878.1) Controller with 2Kx8 On-Board RAM
Datasheet
XTAL1
XTAL2
COM20022
AD0-AD7
AD0-AD2, D3-D7
ALE
A15
A2/BALE
nCS
RXIN
75176B or
Equiv.
RESET
nRESET
nTXEN
nPULSE1
nPULSE2
nRD/nDS
nRD
nWR/DIR
nINTR
nWR
nINT1
GND
Differential Driver
Configuration
8051
Media Interface
may be replaced
*
XTAL1
XTAL2
A0/nMUX
27 pF
with Figure A, B or C.
27 pF
20 MHz
XTAL
+5V
2
RXIN
+5V
Receiver
6
RXIN
HFD3212-002
7
100 Ohm
TXEN
Transmitter
HFE4211-014
nPULSE1
nPULSE2
GND
3
nPULSE1
+5V
2
6
7
2 Fiber Interface
(ST Connectors)
BACKPLANE CONFIGURATION
NOTE: COM20022 must be in backplane mode
FIGURE B
FIGURE A
Figure 5.1 - Multiplexed, 8051 - Like Bus Interface with RS-485 Interface
SMSC COM20022I 3V
Page 17
Revision 02-27-06
DATASHEET