PMC-Sierra, Inc.
PRELIMINARY
PM5381 S/UNI-2488
DATASHEET
PMC-2000489
ISSUE 1
SATURN USER NETWORK INTERFACE FOR 2488 MBIT/S
Pin Name
Type
Pin
No.
Function
TPOH
Input
AH25 The transmit path overhead (TPOH) signal contains the path
overhead bytes (J1, C2, G1, F2, Z3, Z4, and Z5) to be
transmitted in the STS-48c SONET path overhead and the error
masks to be applied on B3 and H4.
A path overhead byte is accepted for transmission when the
external source indicates a valid byte (TPOHEN set high) and
the S/UNI-2488 indicates ready (TPOHRDY set high). The
S/UNI-2488 will ignore the byte on TPOH when TPOHEN is set
low. The TPOHRDY is set low to indicate the S/UNI-2488 is not
ready, and the byte must be re-presented at the next
opportunity.
TPOH is sampled on the rising edge of TOHCLK.
TPOHRDY
Output
AJ25 The transmit path overhead insert ready (TPOHRDY) signal
indicates if the S/UNI-2488 is ready to accept the byte currently
on TPOH.
TPOHRDY is set high during the most significant bit of a POH
byte to indicate readiness to accept the byte on the TPOH input.
This byte will be accepted if TPOHEN is also set high. If
TPOHEN is set low, the byte is invalid and is ignored.
TPOHRDY is set low to indicate that the S/UNI-2488 is unable
to accept the byte on TPOH, and expects the byte to be re-
presented at the next opportunity.
TPOHRDY is updated on the falling edge of TOHCLK.
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
26
PMC [ PMC-SIERRA, INC ]
