AMD SB600 Specifications download pdf (Page 65)

2008 Advanced Micro Devices Inc.

Sample Programs

AMD SB600 BIOS Developer’s Guide (Public Version) Proprietary

Page 65

14.3.2 Multiword DMA Settings

IDE multiword DMA setting is done through registers 44h to 47h. The timing for the multiword

DMA modes has two components – the command width, and the recovery width.

Width MW DMA Mode 2 MW DMA Mode 1 MW DMA Mode 0

Command Width (Cycles) 2h 2h 7h

Recovery Width (Cycles) 0h 1h 7h

The register assignment is as follows:

Sample Program:

The following Assembly language code sample programs the secondary master to multiword

DMA Mode 2 (i.e., it programs register 47h to 20h).

mov dx,0CF8h ; To access PCI configuration space, index register

mov eax,8000A144h ; Device 14h, function 1, registers 44h-47h

out dx,eax ;

mov dx,0CFFh ; To access PCI register 47h

mov al,20h ; Timing for MW DMA Mode 2

out dx,al

14.3.3 UDMA Mode Settings

IDE UDMA enable/disable is set through register 54h, and the UDMA mode is set through the

registers 56h-57h. The register assignments are as follows:

1 2 ... 60 61 62 63 64 65 66 67 68 69 70 ... 97 98

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AMD SB600 Specifications Page 65