SMSC COM20020 manual Figure C

XTAL1

XTAL2

D0-D7

A0

A1

A2

A7

nRES

nIOS R/nW nIRQ1

6801

COM20020
D0-D7
A0/nMUX		RXIN
A1
A2/BALE			75176B or
nCS
		TXEN	Equiv.
nRESET IN		nPULSE1
		nPULSE2
nRD/nDS		GND
nWR/nDIR			Differential Driver
nINTR
			Configuration
XTAL1	XTAL2		* Media Interface
			may be replaced

with Figure A, B or C.

27 pF	20MHz	27 pF
	XTAL

FIGURE 3 - NON-MULTIPLEXED, 6801-LIKE BUS INTERFACE WITH RS-485 INTERFACE

		+5V
	HYC9068 or	10	+	0.47
	HYC9088
		uF		uF
RXIN	RXIN	6
		12
nTXEN	N/C	11		0.01 uF
			5.6K
nPULSE1	nPULSE1			1KV
			1/2W
nPULSE2	nPULSE2		5.6K
GND	17, 19,		1/2W
	4, 13, 14
		3
	0.47		Traditional Hybrid
		-5V	Configuration
	uF
		+ 10
		uF

FIGURE C

14