78P2352 Dual Channel OC-3/STM1-E/E4 Line Interface Unit
PIN DESCRIPTION (CONTINUED)
CONTROL PINS
NAME
PIN
TYPE DESCRIPTION
FIFO Phase-Initialization Control:
Should normally be floating. When asserted, the transmit FIFO pointers are
reset to the respective “centered” states. Also resets the FIERR interrupt bit.
De-assertion edge of FRSTx will resume FIFO operation.
78
CIT
CIT
FRST
•
•
•
Low: Channel 1 FRST assertion
Float: Normal
High: Channel 2 FRST assertion
Loopback Selection:
•
Low: Normal operation
•
Float: Remote Loopback Enable: Recovered receive data and clock
17, 18
LPBKx
are looped back to the transmitter for retransmission.
•
High: Local Loopback Enable: The serial transmit data is looped back
and used as the input to the receiver.
Clock Mode Selection:
Selects the method of inputting transmit data into the chip.
In PARALLEL mode (SDI_PAR high):
•
Low: Parallel transmit clock is input to the 78P2352.
•
Float: Parallel transmit clock is input to the 78P2352. Loop-timing
mode enabled.
•
High: Parallel transmit clock is output from the 78P2352
15
CIT
CKMODE
In SERIAL mode (SDI_PAR low):
•
•
•
Low: Reference clock is synchronous to transmit clock and data.
Data is clocked in with SIxCKP/N and passed through a FIFO
Float: Reference clock is synchronous to transmit data. Clock is
recovered with a CDR and data is passed through a FIFO
High: Reference clock is plesiochronous to transmit data. Clock is
recovered with a CDR and the FIFO is bypassed
18
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
