PMC-Sierra, Inc.
PRELIMINARY
PM5381 S/UNI-2488
DATASHEET
PMC-2000489
ISSUE 1
SATURN USER NETWORK INTERFACE FOR 2488 MBIT/S
Pin Name
RPOHEN
Type
Pin
No.
Function
Output
V28
The receive path overhead enable (RPOHEN) signal
indicates valid path overhead bytes on RPOH
When 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.
The bit interleaved parity error (B3E) signal carries the path
B3E
Output
W29
BIP-8 errors detected for the STS-48c SONET payload.
B3E is set high for one ROHCLK clock cycle for each 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.
9.4
Transmit Section/Line/Path Overhead Insertion Signals (7)
Pin Name
TOHCLK
Type
Pin
No.
Function
Output
AJ27
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.
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
24
PMC [ PMC-SIERRA, INC ]
