Текст страницы
12.27 Read Sector(s) (20h/21h)
The Read Sector(s) command reads one or more sectors of data from disk media, and then transfers the data from
the device to the host.
The sectors are transferred through the Data Register 16 bits at a time.
If an uncorrectable error occurs, the read will be terminated at the failing sector.
Table 173 Read Sector(s) Command (20h/21h)
Command Input
Field
Description
FEATURE
N/A
COUNT
The number of logical sectors to be transferred. A value of 00h
indicates that 256 logical sectors are to be transferred
LBA
LBA of first logical sector to be transferred
DEVICE
Bit Description
7:5 Obsolete
4 Transport Dependent
3:0 Reserved
Command
7:0 20h or 21h
Normal Outputs
See Normal Outputs in Section 12.7 Flush Cache (E7h)
Error Outputs
See Error Outputs in Section 12.18 Read DMA (C8h/C9h)
239
Hard Disk Drive Specification