Read Buffer (E4H); Figure 110. Read Buffer Command (E4H) - IBM IC35L040AVVN07-0 - 40GB IDE Deskstar 120GXP 7200RPM UATA-100 07N9682 Specifications

11.12 Read Buffer (E4h)

Command Block Output
Registers
Register
Data
Feature
Sector Count
Sector Number
Cylinder Low
Cylinder High
Device/Head
Command
Error Register
7 6 5
CRC UNC 0
0 0 0

Figure 110. 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.
7 6 5 4 3 2 1 0
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
1 - 1 D - - - -
1 1 1 0 0 1 0 0
4 3 2 1 0
IDN 0 ABT T0N AMN
0 0 V 0 0
Deskstar 120GXP hard disk drive specifications
Command Block Input
Registers
Register
Data
Error
Sector Count
Sector Number
Cylinder Low
Cylinder High
Device/Head
Status
Status Register
7 6 5 4
BSY RDY DF DSC
0 V 0 –
127
7 6 5 4 3 2 1 0
- - - - - - - -
see below
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
see below
3 2 1 0
DRQ COR IDX ERR
– 0 – V