Avalon-mm burstcount – Altera RapidIO MegaCore Function User Manual

Page 94

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4–48

Chapter 4: Functional Description

Logical Layer Modules

RapidIO MegaCore Function

August 2014

Altera Corporation

User Guide

Translation Window 2

An Avalon-MM address in which the two most significant bits have a value of 2'b11
matches window 2. The RapidIO transaction corresponding to the Avalon-MM
operation has a destination ID value of 0xCC. This value corresponds to processing
endpoint 2.

Figure 4–26

shows address translation window 2.

Avalon-MM Burstcount and Byteenable Encoding in RapidIO Packets

The RapidIO IP core converts Avalon-MM transactions to RapidIO packets. The
Avalon-MM burst count, byteenable, and, in 32-bit variations, address bit 2 values are
translated to the RapidIO packets' read size, write size, and word pointer fields.

For information about the packet size encoding used in the conversion process for
32–bit datapath read requests, refer to

Table 4–11

. For information about the encoding

for 32-bit datapath write requests, refer to

Table 4–12

. For information about the

encoding for 64-bit datapath conversion, refer to

Table 4–13

and

Table 4–14

.

Figure 4–26. Translation Window 2

0x7555999

0x7555999

RapidIO Address [33:0]

{Avalon Address, N’b0}

1

0

0

0

Destination ID

Don’t Care

Don’t Care

0

2

3

3

000000000000000000..............00

Base (register 0x10420)

Mask (register 0x10424)

Offset (register 0x10428)

Control (register 0x1042C)

1

29

29

23

16

30

31

R

R

1

1

1

1

1

1

0

0

0

0

1

1

1

1

30

31

32

33

XAMO

0xCC

Table 4–11. Read Request Size Encoding (32-bit datapath) (Part 1 of 2)

Avalon-MM Values

RapidIO Values

burstcount

(1)

address[0]

(2)

(1'bx)

wdptr

(1'bx)

rdsize

(2)

(4'bxxxx)

1

1

0

1000

1

0

1

1000

2

0

0

1011

3–4

0

1

1011

5–8

0

0

1100

9–16

0

1

1100

17–24

0

0

1101

25–32

0

1

1101

33–40

0

0

1110

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