SanDisk CompactFlash Extreme III - Manual (Page 69)

SanDisk CompactFlash Card OEM Product Manual ATA Command Description
5.1.9 Read Buffer–E4H
The Read Buffer command enables the host to read the current contents of the card's sector
buffer. This command has the same protocol as the Read Sector(s) command.
Table 5-16 Read Buffer
Bit 7 6 5 4 3 2 1 0
Command (7) E4H
C/D/H (6) X Drive X
Cyl High (5) X
Cyl Low (4) X
Sec Num (3) X
Sec Cnt (2) X
Feature (1) X
5.1.10 Read DMA Command–C8H, C9H
The Read DMA command in Table 5-17 executes in a similar manner to the READ
SECTOR(S) command except for the following:
• The host initializes the DMA channel prior to issuing the command.
• Data transfers are qualified by DMARQ and are performed by the DMA channel.
• The device issues only one interrupt per command to indicate that data transfer has termi­
nated and status is available.
During the DMA transfer phase of a Read DMA command, the device provides status of the
BSY bit or the DRQ bit until the command is completed.
Table 5-17 Read DMA Command
Bit 7 6 5 4 3 2 1 0
Command (7) C8H or C9H
C/D/H (6) 1 LBA 1 Drive Head (LBA 27-24)
Cyl High (5) Cylinder High (LBA 23-16)
Cyl Low (4) Cylinder Low (LBA 15-8)
Sec Num (3) Sector Number (LBA 7-0)
Sec Cnt (2) Sector Count
Feature (1) X
© 2007 SanDisk Corporation 5-15 Rev. 12.0, 02/07