PMC-Sierra, Inc.
PRELIMINARY
PM5381 S/UNI-2488
DATASHEET
PMC-2000489
ISSUE 1
SATURN USER NETWORK INTERFACE FOR 2488 MBIT/S
Because DTPA is asserted again on cycle 8, transfers can be conducted again. TENB is
asserted again before cycle 11 to continue the transfer. In cycle 11, TEOP is asserted to indicate
that TDAT[31:0] contains one byte which is the end of the packet. TMOD[1:0] is valid at the same
time to indicate which bytes in TDAT[31:0] contain valid data and thus the last byte of the packet
can be inferred. TERR is also valid during this cycle to indicate whether or not this packet should
be aborted because of an upstream error. If TERR is logic 1, the packet will be aborted by the
S/UNI-2488’s packet processor.
In cycle 12, TENB is deasserted and TSX is asserted to select a different PHY to transfer data to.
TSOP must be high during transfers which contain the first byte of a packet. TEOP must be high
during transfers which contain the last byte of a packet. It is legal to assert TSOP and TEOP at
the same time. This case occurs when TDAT[31:0] contain both the SOP and EOP. When
TSOP is asserted and the previous transfer was not marked with TEOP, the system interface
realigns itself to the new timing, and both the previous packet and the current packet may be
corrupted and aborted.
Figure 25 Single PHY POS-PHY Level 3 Transmit Functional Timing
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TFCLK
TENB
TSX
TSOP
TEOP
TMOD[1:0]
TERR
TDAT[31:0]
TPRTY
DTPA
000 B1-B
B5-B
B41 B45 B49
B53 B57 000 B1-
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
445
PMC [ PMC-SIERRA, INC ]
