1Cadence IP BRA support
2----------------------
3
4Format requirements
5~~~~~~~~~~~~~~~~~~~
6
7The Cadence IP relies on PDI0 for TX and PDI1 for RX. The data needs
8to be formatted with the following conventions:
9
10  (1) all Data is stored in bits 15..0 of the 32-bit PDI FIFOs.
11
12  (2) the start of packet is BIT(31).
13
14  (3) the end of packet is BIT(30).
15
16  (4) A packet ID is stored in bits 19..16. This packet ID is
17      determined by software and is typically a rolling counter.
18
19  (5) Padding shall be inserted as needed so that the Header CRC,
20      Header response, Footer CRC, Footer response are always in
21      Byte0. Padding is inserted by software for writes, and on reads
22      software shall discard the padding added by the hardware.
23
24Example format
25~~~~~~~~~~~~~~
26
27The following table represents the sequence provided to PDI0 for a
28write command followed by a read command.
29
30::
31
32	+---+---+--------+---------------+---------------+
33	+ 1 | 0 | ID = 0 |  WR HDR[1]    |  WR HDR[0]    |
34	+   |   |        |  WR HDR[3]    |  WR HDR[2]    |
35	+   |   |        |  WR HDR[5]    |  WR HDR[4]    |
36	+   |   |        |  pad          |  WR HDR CRC   |
37	+   |   |        |  WR Data[1]   |  WR Data[0]   |
38	+   |   |        |  WR Data[3]   |  WR Data[2]   |
39	+   |   |        |  WR Data[n-2] |  WR Data[n-3] |
40	+   |   |        |  pad          |  WR Data[n-1] |
41	+ 0 | 1 |        |  pad          |  WR Data CRC  |
42	+---+---+--------+---------------+---------------+
43	+ 1 | 0 | ID = 1 |  RD HDR[1]    |  RD HDR[0]    |
44	+   |   |        |  RD HDR[3]    |  RD HDR[2]    |
45	+   |   |        |  RD HDR[5]    |  RD HDR[4]    |
46	+ 0 | 1 |        |  pad          |  RD HDR CRC   |
47	+---+---+--------+---------------+---------------+
48
49
50The table below represents the data received on PDI1 for the same
51write command followed by a read command.
52
53::
54
55	+---+---+--------+---------------+---------------+
56	+ 1 | 0 | ID = 0 |  pad          |  WR Hdr Rsp   |
57	+ 0 | 1 |        |  pad          |  WR Ftr Rsp   |
58	+---+---+--------+---------------+---------------+
59	+ 1 | 0 | ID = 0 |  pad          |  Rd Hdr Rsp   |
60	+   |   |        |  RD Data[1]   |  RD Data[0]   |
61	+   |   |        |  RD Data[3]   |  RD Data[2]   |
62	+   |   |        |  RD HDR[n-2]  |  RD Data[n-3] |
63	+   |   |        |  pad          |  RD Data[n-1] |
64	+   |   |        |  pad          |  RD Data CRC  |
65	+ 0 | 1 |        |  pad          |  RD Ftr Rsp   |
66	+---+---+--------+---------------+---------------+
67