Datasheet

Travelstar 80GN Hard Disk Drive Specification

128

13.15 Read Long (22h/23h)

Table 86: Read Long (22h/23h)

The Read Long command reads the designated one sector of data and the ECC bytes from the disk media. It then

transfers the data and ECC bytes from the device to the host.

After 512 bytes of data have been transferred, the device will keep setting DRQ = 1 to indicate that the device is

ready to transfer the ECC bytes to the host. The data is transferred 16 bits at a time and the ECC bytes are trans-

ferred 8 bits at a time. The number of ECC bytes are 4 or 40 according to the setting of Set Feature option. The

default setting is 4 bytes of ECC data.

The command makes a single attempt to read the data and does not check the data using ECC. Whatever is read is

returned to the host.

Output parameters to the device

Sector Count This indicates the number of continuous sectors to be transferred. The Sector Count must

be set to one.

LBA Low This indicates the sector number of the sector to be transferred. (L = 0)

In LBA mode, this register contains LBA bits 0–7. (L = 1)

LBA High/Mid This indicates the cylinder number of the sector to be transferred. (L = 0)

In LBA mode, this register contains LBA bits 8–15 (Low), 16–23 (High). (L = 1)

H This indicates the head number of the sector to be transferred. (L = 0)

In LBA mode, this register contains LBA bits 24–27. (L = 1)

R This indicates the retry bit; this bit is ignored.

Input parameters from the device

Sector Count This indicates the number of requested sectors not transferred

Command Block Output Registers Command Block Input Registers

Data - - - - - - - - Data - - - - - - - -

Feature - - - - - - - - Error see below

Sector Count 0 0 0 0 0 0 0 1 Sector Count - - - - - - - V

LBA Low V V V V V V V V LBA Low V V V V V V V V

LBA Mid V V V V V V V V LBA Mid V V V V V V V V

LBA High V V V V V V V V LBA High V V V V V V V V

Device 1 L 1 D H H H H Device - - - - - H H H H

Command 0 0 1 0 0 0 1 R Status see below

Error Register Status Register

7654321 0 76543 21 0

CRC UNC 0 IDN 0 ABT T0N AMN BSY RDY DF DSC DRQ COR IDX ERR

000V0V0 V 0V0V- 0- V