TXC-03303-ARPQ Transwitch Corporation, TXC-03303-ARPQ Datasheet - Page 16

• Manufacturer Part Number: TXC-03303-ARPQ
• Manufacturer: Transwitch Corporation

Specifications of TXC-03303-ARPQ

• Lead Free Status / RoHS Status: Compliant

EXTERNAL CLOCK
TEST ACCESS PORT
Symbol
Symbol
TMS
TDO
XCK
TCK
TRS
TDI
Pin No.
Pin No.
148
149
150
151
152
90
I/O/P
I/O/P
O
I
I
I
I
I
TTL8mA
CMOS
TTLp
TTLp
TTLp
TTLp
Type
Type
- 16 -
External Transmit Clock: An external clock having a
frequency of 44.736 MHz and a stability of 20 ppm is
required to meet DSX-3 cross-connect requirements.
The clock duty cycle should be kept to (50 5)%. The
transmit clock is also used to operate the M13E micro-
processor interface. The M13E monitors this clock for
transitions. When a clock failure is detected, the M13E
automatically switches to the receive clock (DS3CR) for
multiplexer and microprocessor operation. Receive loop
timing (a one written to bit 3, LPTIME, in 02H) also
causes the receive clock to become the transmit clock.
Test Mode Select: The signal present on this lead is
used to control boundary scan test operations.
Test Data Input: Serial data input for boundary scan test
messages.
Test Data Output: Serial data output whose information
is clocked out on negative transitions of TCK.
Test Clock: The input clock for boundary scan testing.
The TDI and TMS states are clocked in on positive tran-
sitions.
Test Reset: When an active low signal is applied to this
pin, the M13E Test Access Port (TAP) controller resets
and the boundary scan is disabled. The controller is also
reset by writing F0H followed by 00H to the initialization
register 1FH or by holding the TMS signal lead high for at
least five rising clock transitions of TCK. During power-up
of the M13E, this pin must be held low, to reset the TAP
controller. Failure to do so may cause the TAP controller
to take control of the M13E output pins. When the bound-
ary scan feature is not used, this pin must be held low.
Name/Function
Name/Function
Ed. 4, August 1998
TXC-03303
TXC-03303-MB
M13E