Texas Instruments TMS380C26 specifications Fraq/Txd, Nsrt, Pxtalin, Rcvr/Rxd, Redy, Wrap

TMS380C26

NETWORK COMMPROCESSOR

SPWS010A±APRIL 1992±REVISED MARCH 1993

Terminal Functions (continued)

Network Media Interface ± Token-Ring Mode (TEST1 = H, TEST2 = H)

PIN NAME

NO.

I/O

DESCRIPTION

DRVR

89

OUT

Differential Driver Data Output. These pins are the differential outputs that send the TMS380C16

DRVR

88

transmit data to the TMS38054 for driving onto the ring transmit signal pair.

Frequency Acquisition Control. This TTL output determines the use of frequency or phase acquisition

mode in the TMS38054.

FRAQ/TXD

85

OUT

H

=

Wide range. Frequency centering to PXTALIN by TMS38054.

L

=

Narrow range. Phase-lock onto the incoming data (RCVINA and RCVINB) by the

TMS38054.

Insert Control Signal to the TMS38054. This TTL output signal enables the phantom driver outputs

(PHOUTA and PHOUTB) of the TMS38054, through the watchdog timer, for insertion onto the

Token-Ring.

NSRT

/LPBK

86

OUT

Static High

=

Inactive, phantom current removed (due to watchdog timer)

Static Low

=

Inactive, phantom current removed (due to watchdog timer)

NSRT Low and Pulsed High

=

Active, current output on PHOUTA and PHOUTB

Ring Interface Clock Frequency Control (see Note 5). At 16-Mbps ring speed, this input must be

PXTALIN

/TXC

92

IN

supplied a 32-MHz signal. At 4-Mbps ring speed, the input signal must be 8-MHz and may be the

output from the OSCOUT pin.

Ring Interface Recovered Clock (see Note 5). This input signal is the clock recovered by the

TMS38054 from the Token-Ring received data.

RCLK/RXC

94

IN

For 16-Mbps operation it is a 32-MHz clock.

For 4-Mbps operation it is an 8-MHz clock.

RCVR/RXD

95

IN

Ring Interface Received Data (see Note 5). This input signal contains the data received by the

TMS38054 from the token ring.

Ring Interface Ready. This input pin provides an indication of the presence of received data, as

monitored by the TMS38054 energy detect capacitor.

REDY

/CRS

84

IN

H

=

Not ready. Ignore received data.

L

=

Ready. Received data.

Wire Fault Detect. This signal is an input to the TMS380C16 driven by the TMS38054. It indicates

a current imbalance of the TMS38054 PHOUTA and PHOUTB pins.

WFLT

/COLL

87

IN

H

=

No wire fault detected.

L

=

Wire fault detected.

Internal Wrap Select. This signal is an output from the TMS380C16 to the ring interface to activate

an internal attenuated feedback path from the transmitted data (DRVR) to receive data (RCVR)

signals for bring-up diagnostic testing. When active, the TMS38054 also cuts off the current drive to

WRAP

/TXEN

90

OUT

the transmission pair.

H

=

Normal ring operation.

L

=

Transmit data drives receive data (loopback).

NOTE 5: Pin has an expanded input voltage specification.

16	POST OFFICE BOX 1443 •HOUSTON, TEXAS
	77251±1443