Product manual

SanDisk Industrial Grade CompactFlash 5000 Product Manual

5.1.25

Write Buffer–E8H

The Write Buffer command enables the host to overwrite contents of the card's

sector buffer with any data pattern desired. This command has the same

protocol as the Write Sector(s) command and transfers 512 bytes.

Table 70: Write Buffer

5.1.26

Write DMA Command–CAH, CBH

The Write DMA command in Table 71 performs in a similar manner to WRITE

SECTOR(S) except for the following:

The host initialized 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 terminated and status is available.

During the execution of a Write DMA command, the device provides status of

the BSY bit or the DRQ bit until the command is completed.

Table 71: Write DMA Command

5.1.27

Write Long Sector–32H, 33H

This command is provided for compatibility purposes and is similar to the

Write Sector(s) command except that it writes 516 bytes instead of 512 bytes.

Only single sector Write Long operations are supported. The transfer consists

of 512 bytes of data transferred in word mode followed by 4 bytes of ECC

transferred in byte mode. Because of the unique nature of the solid-state

CompactFlash Memory Card, it cannot use the four bytes of ECC transferred

by the host. The card discards these four bytes and writes the sector with

valid ECC fields. This command has the same protocol as the Write Sector(s)

command.