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
TOHFP
Output
AG25
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:
First A1 byte should be present on TTOH.
First J1 byte should be present on TPOH.
TOHFP can be sampled on the rising edge of TOHCLK.
TOHFP is updated on the falling edge of TOHCLK.
The transmit transport overhead (TTOH) signal contains the
transport overhead bytes (A1, A2, J0, Z0, B1, E1, F1, D1-D3,
H1-H3, B2, K1, K2, D4-D12, Z1/S1, Z2/M1, and E2) to be
transmitted and the error masks to be applied on B1, B2, H1
and H2.
TTOH
Input
Input
AK27
AJ26
TTOH is sampled on the rising edge of TOHCLK.
TTOHEN
The transmit transport overhead insert enable (TTOHEN)
signal controls the insertion of the transmit transport overhead
data which is inserted in the outgoing stream.
When TTOHEN is high during the most significant bit of a TOH
byte on TTOH, the sampled TOH byte is inserted into the
corresponding transport overhead byte positions (A1, A2, J0,
Z0, E1, F1, D1-D3, H3, K1, K2, D4-D12, Z1/S1, Z2/M1, and E2
bytes). When TTOHEN is low during the most significant bit of
a TOH byte on TTOH, that sampled byte is ignored and the
default values are inserted into these transport overhead bytes.
When TTOHEN is high during the most significant bit of the H1,
H2, B1 or B2 TOH byte positions on TTOH, the sampled TOH
byte is logically XOR’ed with the associated incoming byte to
force bit errors on the outgoing byte. A logic low bit in the TTOH
byte allows the incoming bit to go through while a bit set to logic
high will toggle the outgoing bit. A low level on TTOHEN during
the MSB of the TOH byte disables the error forcing for the entire
byte.
TTOHEN is sampled on the rising edge of TOHCLK.
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
25
PMC [ PMC-SIERRA, INC ]
