XRT73R12_07 Datasheet, PDF (13/89 Pages) Exar Corporation – TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT

REV. 1.0.2
XRT73R12
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
GENERAL CONTROL PINS
PIN #
SIGNAL NAME
TYPE
P3
TEST
****
AE25
TRST
I
AB23
TMS
I
AB5
TCK
I
AB4
TDI
I
AE2
TDO
O
DESCRIPTION
Factory Test Mode Input Pin
This pin must be connected to GND for normal operation.
NOTE: This input pin is internally pulled "Low".
Test Reset
Test Boundary Scan
Test Mode Select
Test Boundary Scan
Test Clock
Test Boundary Scan
Test Data Input
Test Boundary Scan
Test Data Output
Test Boundary Scan
MICROPROCESSOR PARALLEL INTERFACE -
PIN #
SIGNAL NAME
TYPE
DESCRIPTION
J26
Pmode
I
This pin controls the Microprocessor Parallel Interface mode.
"High" sets a Synchronous clocked interface mode with a clock from the Host.
"Low" sets an Asynchronous mode where a clock internal to the XRT73R12 will
time the operations.
P24
PCLK
I
High speed clock supplied by the Host to provide timing in the Synchronous
Interface mode. This signal must be a square-wave.
N24
CS
I
Chip Select Input (active low)
Initiates a read or write operation. When "High", no parallel communication is
active between the LIU and the Host.
N22
WR
I
Write Input (active low)
Enables the Host to write data D[7:0] into the LIU register space at address
Addr[7:0].
N23
RD
I
Read Input (active low)
Commands the LIU to transfer the contents of a register specified by Addr[7:0]
to the Host.
N25
RDY
O Ready Line Output (active low)
Provides a handshake between the LIU and the Host that communicates when
an operation has been completed.
NOTE: This pin must be pulled "High" with a 3kΩ ± 1% resistor.
10