Write Command - Seagate STT20000A Product Manual

Chapter 5

Write command

Bit 7
Byte
0
1
1
2 (MSB)
3
4
5
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6 5
The Transfer Length specifies the number of fixed 512 byte blocks to be transferred.
A transfer length of 0 indicates that no data is to be transferred but is used on some
drives to put DSC into write buffer mode.
The DSC bit is reset (0) after this command is accepted and all data has been
transferred. This bit is set (1) when there are at least 52 empty blocks in the buffer
available for the next WRITE command. Issuing a WRITE command when the DSC
bit is reset (0) will keep the ATA bus busy (BSY=1) until buffer
4 3
Operation code (0Ah)
Reserved
Reserved
Transfer Length
Reserved
ATAPI Interface
2 1
1 (Fixed)
STT20000A Product Manual
0
(LSB)