PM5381-BI PMC-Sierra, Inc., PM5381-BI Datasheet - Page 56

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

9.4
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2000489, Issue 4
Transmit Section/Line/Path Overhead Insertion Signals (7)
Pin Name
B3E
Pin Name
TOHCLK
TOHFP
Type
Output
Type
Output
Output
Pin
No.
W29
Pin
No.
AJ27
AG25
Function
The bit interleaved parity error (B3E) signal carries the path
BIP-8 errors detected for the STS-48c SONET payload.
This signal is not valid for non-STS-48c configurations.
B3E is set high for one ROHCLK clock cycle for each STS-
48c path BIP-8 error detected (up to eight errors per path per
frame).
When BIP-8 errors are treated on a block basis, B3E is set
high for one ROHCLK clock cycle for up to eight path BIP-8
errors detected (up to one error per path per frame).
Path BIP-8 errors are detected by comparing the extracted
path BIP-8 byte (B3) with the computed path BIP-8 byte of the
previous frame.
B3E is updated on the falling edge of ROHCLK.
Function
The transmit overhead clock (TOHCLK) signal provides
timing for the transmit section, line and path overhead
insertion.
TOHCLK is a nominal 20.736MHz clock generated by
gapping a 25.92MHz clock. TOHCLK has a 33% high duty
cycle.
TOHFP and TPOHRDY are updated on the falling edge of
TOHCLK.
TTOH, TTOHEN, TPOH and TPOHEN are sampled on the
rising edge of TOHCLK.
The transmit overhead frame pulse (TOHFP) signal
provides timing for the transmit section, line and path
overhead insertion.
TOHFP is used to indicate the most significant bit (MSB) on
TTOH and TPOH.
TOHFP is set high when the MSB of the:
TOHFP can be sampled on the rising edge of TOHCLK.
TOHFP is updated on the falling edge of TOHCLK.
First A1 byte should be present on TTOH.
First J1 byte should be present on TPOH.
S/UNI-2488 Telecom Standard Product Datasheet
Released
56