Addressing Of Hdd Registers - Hitachi HTS421212H9AT00 - Travelstar 120 GB Hard Drive Specifications

7.11 Addressing of HDD registers

The host addresses the drive through a set of registers called a Task File. These registers are mapped into the host's
I/O space. Two chip select lines (CS0- and CS1-) and three address lines (DA00–02) are used to select one of these
registers, while a DIOR- or DIOW- is provided at the specified time.
The chip select line CS0- is used to address the Command Block registers while the CS1- is used to address Con-
trol Block registers.
The following table shows the I/ O address map.
CS0- CS1- DA02
0 1
0 1
0 1
0 1
0 1
0 1
0 1
0 1
1 0
1 0
DA01 DA00
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
1 1 0
1 1 1
Travelstar 4K120 Hard Disk Drive Specification
DIOR- = 0 (Read)
Command Block Registers
Data Reg.
Error Reg.
Sector count Reg.
LBA low Reg
LBA mid Reg.
LBA high Reg.
Drive Reg.
Status Reg.
Control Block Registers
Alt. Status Reg.
Drive address Reg.
56
DIOW- = 0 (Write)
Data Reg.
Features Reg.
Sector count Reg.
LBA low Reg.
LBA mid Reg.
LBA high Reg.
Device Reg.
Command Reg.
Device control Reg.
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