PM7344 S/UNI-MPH
DATA SHEET
PMC-950449
ISSUE 6
MULTI-PHY USER NETWORK INTERFACE
The S/UNI-MPH is configured for multi-PHY addressing (MPHEN = 1). The
TCAMPH output is updated with the transmit cell available status of the PHY
selected by the TWA[1:0] inputs in the previous cycle. TWA[1:0] is latched while
TWRMPHB is high. On the high to low transition of TWRMPHB, the PHY
selected by the latched address (in this case PHY #1, TWA[1:0] = 0H) begins to
accept its 53 octet cell. During this transfer, the three remaining cell available
signals (from PHY #2, #3, and #4) can be polled as required. The cell available
status of PHY #1 indicates that a cell is available while the cell transfer is in
progress. In the diagram above, at the end of the cell transfer from PHY #1,
PHY #4 (TWA[1:0] = 3H) has a cell available. TWRMPHB is brought high for
one clock cycle to latch the new address. TWRMPHB is then brought low and
the cell transfer to PHY #4 proceeds.
Figure 25
- Multi-PHY Addressing Receive Cell Interface (MPHEN = 1)
RFCLK
• • •
RRA [ 1 :0 ]
0
0
1
1
2
• • •
• • •
2
3
3
0
0
1
RCA MPH
RRDMPHB
RSOC
• • •
• • •
RDA T[ 7 :0 ]
RXPRTY
H1
H2
• • • P4 6 P4 7 P4 8
• • •
H2
H1
The S/UNI-MPH is configured for multi-PHY addressing (MPHEN = 1). The
RCAMPH output is updated with the receive cell available status of the PHY
selected by the RRA[1:0] inputs in the previous cycle. RRA[1:0] is latched while
RRDMPHB is high. On the high to low transition of RRDMPHB, the PHY
selected by the latched address (in this case PHY #1, RRA[1:0] = 0H) begins
outputting its 53 octet cell. During this transfer, the three remaining cell available
signals (from PHY #2, #3, and #4) can be polled as required. The cell available
status of PHY #1 indicates that a cell is available while the cell transfer is in
progress. In the diagram above, at the end of the cell transfer from PHY #1,
PHY #4 (RRA[1:0] = 3H) has a cell available. RRDMPHB is brought high for one
clock cycle to latch the new address and to avoid contention on the tristateable
signals. RRDMPHB is then brought low and the cell transfer from PHY #4
proceeds.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
229
PMC [ PMC-SIERRA, INC ]
