XTAL1 | COM20020 |
| |
|
| ||
XTAL2 |
|
|
|
|
| ||
ALE | A2/BALE | RXIN |
|
A15 | nCS |
| |
|
| ||
RESET | nRESET IN | nTXEN | 75176B or |
Equiv. | |||
|
| nPULSE1 |
|
nRD | nRD/nDS | nPULSE2 |
|
nWR | nWR/DIR | GND |
|
nINT1 | nINTR |
| |
|
| ||
|
|
| Differential Driver |
| A0/nMUX |
| Configuration |
|
|
| |
| XTAL1 | XTAL2 | *Media Interface |
| may be replaced | ||
|
|
| |
8051 |
|
| with Figure A, B or C. |
27 pF | 27 pF |
| |
|
| ||
FIGURE 2 - MULTIPLEXED, 8051-LIKE BUS INTERFACE WITH RS-485 INTERFACE
RXIN
TXEN
nPULSE1
nPULSE2
GND
+5V
100 Ohm
+5V
2
6 Receiver
RXIN
7
Transmitter
3
nPULSE1
+5V
2
6
7
2 Fiber Interface
(ST Connectors)
BACKPLANE CONFIGURATION
NOTE: COM20020 must be in backplane mode
FIGURE A | FIGURE B |
13
