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11.18 Read Buffer (E4h)
Com m and Block Output Registers
Register
7
6
Data
-
-
Feature
-
-
Sector Count
-
-
Sector Number
-
-
Cylinder Low
-
-
Cylinder High
-
-
Device/Head
1
-
Command
1
1
Error Register
7
6
5
4
CRC UNC
0
IDN
0
0
0
0
Table 137 Read Buffer Command (E4h)
The Read Buffer command transfers a sector of data from the sector buffer of device to the host.
The sector is transferred through the Data Register 16 bits at a time.
The sector transferred will be from the same part of the buffer written to by the last Write Buffer command. The
contents of the sector may be different if any reads or writes have occurred since the Write Buffer command was
issued.
5
4
3
2
1
0
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
1
D
-
-
-
-
1
0
0
1
0
0
3
2
1
0
0
ABT
T0N AMN
0
V
0
0
Western Digital Hard Disk Drive OEM Specification
Com m and Block Input Registers
Register
7
6
5
Data
-
-
-
Error
...See Below ...
Sector Count
-
-
-
Sector Number
-
-
-
Cylinder Low
-
-
-
Cylinder High
-
-
-
Device/Head
-
-
-
Status
...See Below ...
Status Register
7
6
5
4
BSY
RDY
DF
DSC DRQ COR
0
V
0
-
166
4
3
2
1
0
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
3
2
1
0
IDX
ERR
-
0
-
V
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