PMC-Sierra, Inc.
PRELIMINARY
PM5381 S/UNI-2488
DATASHEET
PMC-2000489
ISSUE 1
SATURN USER NETWORK INTERFACE FOR 2488 MBIT/S
Pin Name
TPOHEN
Type
Pin
No.
Function
Input
AK26 The transmit path overhead insert enable (TPOHEN) signal
controls the insertion of the transmit path overhead data which
is inserted in the outgoing stream.
TPOHEN shall be set high during the most significant bit of a
POH byte to indicate valid data on the TPOH input. This byte
will be accepted for transmission if TPOHRDY is also set high. If
TPOHRDY is set low, the byte is rejected and must be re-
presented at the next opportunity.
Accepted bytes sampled on TPOH are inserted into the
corresponding path overhead byte positions (for the J1, C2, G1,
F2, Z3, Z4, and Z5 bytes). The byte on TPOH is ignored when
TPOHEN is set low during the most significant bit position.
When the byte at the B3 or H4 byte position on TPOH is
accepted, it is used as an error mask to modify the
corresponding transmit B3 or H4 path overhead byte,
respectively. The accepted error mask is XOR’ed with the
corresponding B3 or H4 byte before it is transmitted.
TPOHEN is sampled on the rising edge of the TOHCLK.
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
27
PMC [ PMC-SIERRA, INC ]
