PMC-Sierra, Inc.
PRELIMINARY
PM5381 S/UNI-2488
DATASHEET
PMC-2000489
ISSUE 1
SATURN USER NETWORK INTERFACE FOR 2488 MBIT/S
9.3
Receive Section/Line/Path Overhead Extraction Signals (6)
Pin Name
ROHCLK
Type
Pin
No.
Function
Output
V30
The receive overhead clock (ROHCLK) signal provides
timing for the receive section, line and path overhead
extraction.
ROHCLK is a nominal 20.736 MHz clock generated by
gapping a 25.92 MHz clock. ROHCLK has a 33% high duty
cycle.
ROHFP, RTOH, RPOH, RPOHEN, B3E are updated on the
falling edge of ROHCLK.
ROHFP
Output
U27
The receive overhead frame pulse (ROHFP) signal provides
timing for the receive section, line and path overhead
extraction.
ROHFP is used to indicate the most significant bit (MSB) on
RTOH, RPOH and the first possible path BIP error on B3E.
ROHFP can be sample on the rising edge of ROHCLK.
ROHFP is updated on the falling edge of ROHCLK.
RTOH
RPOH
Output
Output
V29
The receive transport overhead (RTOH) signal contains the
received transport overhead bytes (A1, A2, J0, Z0, B1, E1,
F1, D1-D3, H1-H3, B2, K1, K2, D4-D12, Z1/S1, Z2/M1, and
E2) extracted from the incoming stream.
RTOH is updated on the falling edge of ROHCLK.
V27
The receive path overhead (RPOH) signal contains the
received path overhead bytes (J1, B3, C2, G1, F2, H4, Z3, Z4,
and Z5) extracted from the STS-48c/STM16c SONET/SDH
path overhead
The RPOHEN signal is set high to indicate valid path
overhead bytes on RPOH.
RPOH is updated on the falling edge of ROHCLK.
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
23
PMC [ PMC-SIERRA, INC ]
