GT-64260A Design Guide
Doc. No. MV-S300165-00, Rev. A
CONFIDENTIAL
Copyright © 2002 Marvell
Page 156
Document Classification: Proprietary Information
May 21, 2002, Preliminary
Second phase - Pad[31:0] = 0x77665544
Pad[63:32] = don’t care
Here is how it looks on a 32 bit PCI bus:
In case of starting address with offset 0:
First phase - Pad[31:0] = 0x33221100
Second phase - Pad[31:0] = 0x77665544
In case of starting address with offset 4:
First phase - Pad[31:0] = 0x33221100
Second phase - Pad[31:0] = 0x77665544
shows how the data looks on the SDRAM bus.
shows the necessary swaps for all eight options.
Table 38:
Master Swapping on the SDRAM Bus
Swap Type
Starting Address with Offset 0
Starting Address with Offset 4
Byte Swap
Sdata[63:0] – 0x0011223344556677
Phase 1 - Sdata[63:0] –
0xxxxxxxxx00112233
Phase 2 - Sdata[63:0] –
0x44556677xxxxxxxx
Byte and
Word Swap
Sdata[63:0] – 0x4455667700112233
Phase 1 – Sdata[63:0] –
0x00112233xxxxxxxx
Phase 2 – Sdata[63:0]–
0xxxxxxxxx44556677
Word Swap
Sdata[63:0] – 0x3322110077665544
Phase 1 – Sdata[63:0] –
0xxxxxxxxx33221100
Phase 2 – Sdata[63:0] –
0x77665544xxxxxxxx
No Swap
Sdata[63:0] – 0x7766554433221100
Phase 1 – Sdata[63:0] –
0x33221100xxxxxxxx
Phase 2 – Sdata[63:0] –
0xxxxxxxxx77665544
Table 39:
Swapping for All Eight Options
PCI Width
PCI Endianess
Core Endianess
Swap Needed
64
Little
Little
No swap
64
Little
Big
Byte swap
64
Big
Little
Byte swap
64
Big
Big
No swap