Chapter 5ATAPI Interface
Write command
Bit | 7 | 6 | 5 | 4 |
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0 |
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| Operation code (0Ah) |
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1 |
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| Reserved |
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| 1 (Fixed) | |
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1 |
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2 | (MSB) |
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3 |
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| Transfer Length |
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4 |
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5 |
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| Reserved |
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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
Page 60 | STT8000A Product Manual |