![](http://datasheet.mmic.net.cn/330000/PM5381_datasheet_16444347/PM5381_58.png)
PRELIMINARY
PMC-Sierra, Inc.
PM5381 S/UNI-2488
DATASHEET
PMC-2000489
ISSUE 1
SATURN USER NETWORK INTERFACE FOR 2488 MBIT/S
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
37
Pin Name
Type
Pin
No.
Function
TMOD[1:0]
Input
B17
A18
The POS-PHY
transmit word modulo
(TMOD[1:0]) bus
indicates the size of the current word when configured for packet
mode. During a packet transfer, every word on TDAT[31:0] must
contain four valid bytes of packet data except at the end of the
packet where the word is composed of 1, 2, 3, or 4 valid bytes.
The number of valid bytes in this last word is specified by
TMOD[1:0]
TMOD[1:0] = “00” TDAT[31:0] valid
TMOD[1:0] = “01” TDAT[31:8] valid
TMOD[1:0] = “10” TDAT[31:16] valid
TMOD[1:0] = “11” TDAT[31:24] valid
TMOD[1:0] is considered valid only when TENB is
simultaneously asserted. TMOD[1:0] is only used for POS
operation and is sampled on the rising edge of TFCLK.
9.6
APS Serial Data Interface (20)
Pin Name
Type
Pin
No.
Function
APSI+[4]
APSI-[4]
APSI+[3]
APSI-[3]
APSI+[2]
APSI-[2]
APSI+[1]
APSI-[1]
Analog
LVDS
Input
Y4
Y3
Y2
Y2
AA3
AA2
AB4
AB3
The differential
APSI
input (APSI+/-[4:1]) serial data links
carries SONET/SDH OC-48 frame data from a mate in bit
serial format. Each differential pair carries a constituent
OC-12 of the data stream. Data on APSI+/-[4:1] is encoded in
an 8B/10B format extended from IEEE Std. 802.3. The
8B/10B character bit ‘a(chǎn)’ is transmitted first and the bit ‘j’ is
transmitted last.
When in working mode as set using the APSMODE input and
the MODE[1:0] register bits in the S/UNI-2488 Master Reset,
Configuration and Loopback register, the APSI+/-[4:1] signals
carry the receive data from the protect mate. When in protect
mode, the APSI+/-[4:1] signals carry the transmit data from
the working mate.
The four differential pairs in APSI+/-[4:1] are frequency locked
but not phase locked. APSI+/-[4:1] are nominally 777.6 Mbps
data streams.