Multi-Word Dma; Set Multiple Mode (C6H) - Samsung WA31273A Technical Manual

This command is used by the host to establish the following parameters which affect the
execution of certain drive features as shown in Table 6-8.
Code
02h
03h
33h
44h
55h
77h
82h
88h
99h
AAh
BBh
When the drive receives this command, it sets BSY, checks the contents of the Feature
register, clears BSY, and generates an interrupt. If the value in the Feature Register is not
supported or is invalid, the drive posts an Aborted Command error. Refer to section
6.6.3 for protocol.
A host can choose the transfer mechanism by Set Transfer Mode and specifying a value
in the Sector Count Register. The upper 5 bits define the type of transfer and the low
order 3 bits encode the mode value.
Block transfer (default)
Single word DMA
Mode x

Multi-word DMA

Mode 0

6-4-18 Set Multiple Mode (C6h)

This command enables the drive to perform Read and Write Multiple operations and
establishes the block count for these commands. Refer to section 6.6.3 for protocol.
The Sector Count Register is loaded with the number of sectors per block. Drives
WA31273A / WA32543A / WA33203A / WA32163A / WA31083A / WA32162A 6-33
Table 6-8. Set Feature Register Definitions
Enable Write Cache
Set transfer mode based on value in Sector Count register
Disable Retry
11 bytes of ECC apply on Read Long/Write Long commands
Disable read look-ahead feature
Disable ECC
Disable Write Cache
Enable ECC
Enable Retries
Enable read look-ahead feature
4 bytes of ECC apply on Read Long/Write Long commands
AT INTERFACE and ATA COMMANDS
Description
00000 000
00010 0xx
00100 000