13.15 Read Long (22h/23h)
see belowStatus0 0 1 0 0 0 1 RCommand
- - - - H H H HDevice/Head1 L 1 D H H H HDevice/Head
V V V V V V V VCylinder HighV V V V V V V VCylinder High
V V V V V V V VCylinder LowV V V V V V V VCylinder Low
V V V V V V V VSector NumberV V V V V V V VSector Number
- - - - - - - VSector Count0 0 0 0 0 0 0 1Sector Count
see belowError- - - - - - - -Feature
- - - - - - - -Data- - - - - - - -Data
7 6 5 4 3 2 1 0Register7 6 5 4 3 2 1 0Register
Command Block Input RegistersCommand Block Output Registers
V-0-V0V0V0V0V000
ERRIDXCORDRQDSCDFRDYBSYAMNT0NABT0IDN0UNCCRC
0123456701234567
Status RegisterError Register
Figure 94. Read Long command (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 transferred 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.
Sector Number 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)
Cylinder High/Low 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)
Travelstar 48GH, 30GN & 15GN hard disk drive specifications
141
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