TI380C27 Datasheet, PDF (13/77 Pages) Texas Instruments – DUAL-PROTOCOL COMMPROCESSOR

TI380C27
DUAL-PROTOCOL COMMPROCESSOR
SPWS014A – APRIL 1994 – REVISED MARCH 1995
Pin Functions (Continued)
PIN
NAME
DRVR
DRVR
FRAQ
NSRT
PXTALIN
RCLK
RCVR
REDY
WFLT
WRAP
Network Media Interface — Token-Ring Mode ( TEST1 = H, TEST2 = H)
I/O ^†
NO.
DESCRIPTION
115
114
O
Differential-driver data output. DRVR and DRVR are the differential outputs that send the TI380C27
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.
111
O
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.
112
O
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, PXTALIN must be
118
I
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
120
I
token-ring received data. For 16-Mbps operation, RCLK is a 32-MHz clock; for 4-Mbps operation,
RCLK is an 8-MHz clock.
121
I
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.
110
I
H = Not ready. Ignore received data.
L = Ready. Received data.
Wire-fault detect. WFLT is an input to the TI380C27 driven by the TMS38054. WFLT indicates a current
imbalance of the TMS38054 PHOUTA and PHOUTB pins.
113
I
H = No wire fault detected
L = Wire fault detected
Internal wrap select. WRAP is an output from the TI380C27 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
116
O
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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