TI380C30 Datasheet, PDF (15/78 Pages) Texas Instruments – INTEGRATED TOKEN-RING COMMPROCESSOR AND PHYSICAL-LAYER INTERFACE

TI380C30
INTEGRATED TOKEN-RING
COMMPROCESSOR AND PHYSICAL-LAYER INTERFACE
SPWS016A – NOVEMBER 1994 – REVISED JULY 1995
Pin Functions (Continued)
PIN
NAME
NO.
I/O/E†
DESCRIPTION
WRAP
Internal wrap mode control. WRAP indicates the TI380C30 has placed the physical layer in the
170
O
loopback-wrap mode for adapter self test.
H = Normal ring operation
L = Physical-layer wrap mode selected
XFAIL
External fail-to-match signal. An enhanced address copy option (EACO) device uses XFAIL to indicate
to the TI380C30 that it should not copy the frame nor set the ARI/FCI bits in a token-ring frame due
to an external address match.The ARI/FCI bits in a token-ring frame can be set due to an internal
117
I
address-matched frame. If an EACO device is not used, XFAIL must be left unconnected. XFAIL is
ignored when CAF mode is enabled [see table in XMATCH description section (see Note 1)].
H = No address match by external address checker
L = External address-checker-armed state
External match signal. An EACO device uses XMATCH to indicate to the TI380C30 to copy the frame
and set the ARI/FCI bits in a token-ring frame. If an EACO device is not used, XMATCH must be left
unconnected. XMATCH is ignored when CAF mode is enabled (see Note 1).
XMATCH
H = Address match recognized by external address checker
L = External address-checker-armed state
118
I
XMATCH
XFAIL FUNCTION
0
0
Armed (processing frame data)
0
1
Do not externally match the frame (XFAIL takes precedence)
1
0
Copy the frame
1
1
Do not externally match the frame (XFAIL takes precedence)
Hi-Z
Hi-Z Reset state (adapter not initialized)
XMT+
XMT–
143
144
E
Transmit differential outputs XMT+ and XMT– provide a low-impedance differential source for line drive
via filtering and transformer isolation.
XT1
130
I
XTAL connection. An 8-MHz crystal network can be connected here to provide a reference clock for
XT2
132
E
the TI380C30. Alternatively, an 8-MHz TTL clock source can be connected to XT1.
† _{I = input, O = output, E = provides external-component connection to the internal circuitry for tuning}
NOTE 1: Pin has an internal pullup device to maintain a high-voltage level when left unconnected (no etch).
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