SMSC TMC2005-JT PORT GROUP, GROUP A, GROUP B, FUNCTION, RX POLAR, TX POLAR, EXTENSION, SA, SB, SE, LA, LB, LE, MA, MB, ME, TRANSCEIVER, Various Setup, Note for Unused port

ARCNET 5 Port HUB Controller

Datasheet

PORT GROUP

The five ports can be divided into three groups (group A: two ports, group B: two ports, extension port: one port) and each group can select TX/RX polar, noise cut mode, and big jitter mode respectively. Select pins for each group are as follows:

		FUNCTION		GROUP A		GROUP B			EXTENSION
		RECEIVE		RXINA0, 1		RXINB0, 1			EXTRX
		TRANSMIT		TXENA0, 1		TXENB0, 1			EXTTX
		RX POLARITY		SA				SB	SE
		TX POLARITY		LA				LB	LE
		TX CONTROL		MA			MB		ME
		NOISE CUT		nMBA			nMBB		nMBE
		BIG JITTER		nBJA			nBJB		nBJE
		EXTENSION							nEXTOD
Various Setup
			Example For Operation Mode Setup To Each Port
		SA, SB, SE	LA, LB, LE	MA, MB, ME	RX POLAR			TX POLAR	TRANSCEIVER
	1		0	1	Active Low			Active Low	HYC2485S/HYC2488S
	0		1	0	Active High			Active High	Optical Transceiver
	0		0	1	Active High			Active Low	HYC9088/HYC9068
	1		1	1	Active Low			Active High	RS485 Transceiver

Note for Unused port

Unused ports can be left open because RX port (RX input), RX polar (S input), TX polar (L input), TX control (M input) pins have internal pull-up resistors. Because of internal pull-up resistors, select pins for noise cut (nMB input), big jitter (nBJ input) can be left open when used for setting “OFF”.

Example for Power-On Reset Circuit

FIGURE 9 - POWER-ON RESET

Revision 1.1 (07-24-07) Page 20 SMSC TMC2005-JT

DATASHEET