TI380C25 Datasheet, PDF (14/71 Pages) Texas Instruments – TOKEN-RING COMMPROCESSOR

TI380C25
TOKEN-RING COMMPROCESSOR
SPWS012 – JANUARY 1995
Pin Functions (Continued)
PIN
NAME
NO.
DRVR
115
DRVR
114
FRAQ
111
NSRT
112
PXTALIN
118
RCLK
120
RCVR
121
REDY
110
WFLT
113
WRAP
116
I / O^†
O
O
O
I
I
I
I
I
O
Token-Ring Media Interface
DESCRIPTION
Differential-driver data output. DRVR and DRVR are the differential outputs that send the TI380C25
transmit data to the TMS38054 for driving onto the ring-transmit-signal pair.
Frequency-acquisition control. FRAQ determines the use of frequency- or phase-acquisition mode in
the TMS38054.
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. NSRT enables the phantom-driver outputs (PHOUTA and
PHOUTB) of the TMS38054, through the watchdog timer, for insertion onto the token ring.
Static high
Static low
NSRT low and pulsed high
= Inactive, phantom current removed (due to watchdog timer)
= Inactive, phantom current removed (due to watchdog timer)
= Active, current output on PHOUTA and PHOUTB
Ring-interface clock-frequency control (see Note 5). At 16-Mbps ring speed, PXTALIN must be
supplied a 32-MHz signal. At 4-Mbps ring speed, PXTALIN must be 8 MHz and can be the output from
OSCOUT.
Ring-interface recovered clock (see Note 5). RCLK is the clock recovered by the TMS38054 from the
token-ring received data. For 16-Mbps operation, RCLK is a 32-MHz clock; for 4-Mbps operation,
RCLK is an 8-MHz clock.
Ring-interface received data (see Note 5). RCVR contains the data received by the TMS38054 from
the token ring.
Ring-interface ready. REDY indicates the presence of received data as monitored by the TMS38054
energy-detect capacitor.
H = Not ready. Ignore received data.
L = Ready. Received data.
Wire-fault detect. WFLT is an input to the TI380C25 driven by the TMS38054. WFLT indicates a current
imbalance of the TMS38054 PHOUTA and PHOUTB pins.
H = No wire fault detected
L = Wire fault detected
Internal wrap select. WRAP is an output from the TI380C25 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 the
transmission pair.
H = Normal ring operation
L = Transmit data drives receive data (loopback).
† _{I = input, O = output}
NOTE 5: Pin has an expanded input-voltage specification.
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