COM20020I_0609 Datasheet, PDF (16/69 Pages) SMSC Corporation – 5Mbps ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM

5Mbps ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
XTAL1
XTAL2
AD0-AD7
ALE
A15
RESET
nRD
nWR
nINT1
8051
COM20022
AD0-AD2, D3-D7
A2/BALE
nCS
nRESET
nRD/nDS
nWR/DIR
nINTR
RXIN
nTXEN
nPULSE1
nPULSE2
GND
75176B or
Equiv.
Differential Driver
Configuration
A0/nMUX ^XTAL1 XTAL2
27 pF
20 MHz
XTAL
27 pF
*Media ^Interface
may be replaced
with Figure A, B or C.
RXIN
TXEN
nPULSE1
nPULSE2
GND
+5V
100 Ohm
BACKPLANE CONFIGURATION
FIGURE A
RXIN
+5V
2
6 Receiver
HFD3212-002
7
nPULSE1
+5V
Transmitter
3 ^HFE4211-014
2
6
7
2 Fiber Interface
(ST Connectors)
NOTE: COM20022 must be in backplane mode
FIGURE B
Figure 2 - Multiplexed, 8051-Like Bus Interface With RS-485 Interface
SMSC COM20020I 3.3V Rev.E
Page 16
DATASHEET
Revision 09-11-06