PM7311 pmc-sierra, PM7311 Datasheet - Page 267

• Manufacturer Part Number: PM7311
• Description: Freedm 84a1024l Assp Telecom Standard Datasheet
• Manufacturer: pmc-sierra

Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2021832, Issue 2
Figure 43 Receive APPI Timing (Auto Deselection)
RXDATA[15:0]
Figure 43 shows the transfer of a 100 word packet across the Rx APPI from FREEDM 84A1024L
device 0, channel 2 followed by the transfer of a 2 word packet from FREEDM 84A1024L device
0, channel 8. More importantly, Figure 43 illustrates that, for back-to-back transfers from the
same FREEDM 84A1024L (device 0), it must be reselected before any further data is provided on
the Rx APPI.
At the end of the first 100 word packet transfer across the Rx APPI, the FREEDM 84A1024L
automatically deselects and must be reselected before the second two word packet is transferred.
When the external controller samples REOP high, it recognizes that the burst transfer has
completed. Two RXCLK cycles later, the external controller reselects FREEDM 84A1024L
device 0 by setting RENB high and placing address 0 on the RXADDR[3:0] signals. When the
FREEDM 84A1024L samples RENB low, it begins the next data transfer as before.
Figure 44 Receive APPI Timing (Optimal Reselection)
RXDATA[15:0]
Figure 44 shows optimal bandwidth utilization across the Rx APPI.
With knowledge that the maximum burst data transfer (excluding Any-PHY channel address
prepend) is 256 bytes, i.e. 128 words, the external controller sets RENB high when the 127
(D126) is placed on RXDATA[15:0] in anticipation of the end of a burst transfer. The FREEDM
RXADDR[3:0]
RXADDR[3:0]
RXCLK
RXCLK
RMOD
RSOP
RMOD
REOP
REOP
RSOP
RENB
RERR
RENB
RERR
RVAL
RVAL
RPA
RSX
RPA
RSX
Dev 0
Dev 0
NULL
NULL
Dev 7
Dev 0
Dev 7
Dev 0
NULL
CH 2
Dev 6
Dev 7
NULL
CH 2
D0
FREEDM 84A1024L ASSP Telecom Standard Product Data Sheet
Dev 0
Dev 0
NULL
D1
Dev 6
Dev 7
D0
Dev 4
D98
NULL
D1
D99
Dev 0
Dev 0
NULL
NULL
D125
Dev 4
Dev 0
Dev 0
D126
NULL
D127
NULL
Dev 0
Dev 4
Dev 0
Dev 3
CH 8
NULL
Dev 0
Dev 0
CH 2
D0
Dev 0
Dev 0
NULL
Dev 2
Dev 3
D1
Dev 4
D128
Released
th
267
word
Dev 3
NULL
Dev 2
NULL