PM5381-BI PMC-Sierra, Inc., PM5381-BI Datasheet - Page 55

• Manufacturer Part Number: PM5381-BI
• Description: ATM UNI, Single Channel ATM PHY Interface for 2488.32Mbps
• Manufacturer: PMC-Sierra, Inc.

9.3
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2000489, Issue 4
Receive Section/Line/Path Overhead Extraction Signals (6)
Pin Name
ROHCLK
ROHFP
RTOH
RPOH
RPOHEN
Type
Output
Output
Output
Output
Output
Pin
No.
V30
U27
V29
V27
V28
Function
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, and RALM are
updated on the falling edge of ROHCLK.
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 sampled on the rising edge of ROHCLK.
ROHFP is updated on the falling edge of ROHCLK.
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, E2,
and all undefined transport overhead) extracted from the first
STS-12 (RRMP #1 only) of the incoming stream.
RTOH is updated on the falling edge of ROHCLK.
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. Path overhead can only be
extracted from the first STS-12 slice in this manner.
The RPOHEN signal is set high to indicate valid path
overhead bytes on RPOH.
RPOH is updated on the falling edge of ROHCLK.
The receive path overhead enable (RPOHEN) signal
indicates valid path overhead bytes on RPOH
When the RPOHEN signal is set high, the corresponding path
overhead byte presented on RPOH is valid. When RPOHEN
is set low, the corresponding path overhead byte presented
on RPOH is invalid.
RPOHEN is updated on the falling edge of ROHCLK.
S/UNI-2488 Telecom Standard Product Datasheet
Released
55