7K200 SATA OEM Specification
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11.2
Command register
This register contains the command code being sent to the device. Command execution begins
immediately after this register is written. The command set is shown in
“Table 40 Command set” on
page 74.
All other registers required for the command must be set up before writing the Command Register.
11.3
Device Control Register
Device Control Register
7 6 5 4 3 2 1 0
- - - - 1
SRST
-IEN
0
Table 25 Device Control Register
Bit Definitions
SRST (RST)
Software Reset. The device is held reset when RST=1. Setting RST=0 reenables the device.
The host must set RST=1 and wait for at least 5 microseconds before setting RST=0, to
ensure that the device recognizes the reset.
-IEN
Interrupt Enable. When IEN=0, and the device is selected, device interrupts to the host will
be enabled. When IEN=1, or the device is not selected, device interrupts to the host will be
disabled.
11.4
Device Register
Device Register
7 6 5 4 3 2 1 0
- L - 0
HS3
HS2
HS1
HS0
Table 26 Device Register
This register contains the device and head numbers.
Bit Definitions
L
Binary encoded address mode select. When L=0, addressing is by CHS mode. When L=1,
addressing is by LBA mode.
HS3,HS2,HS1,HS0
The HS3 through HS0 contain bits 24-27 of the LBA. At command completion, these bits
are updated to reflect the current LBA bits 24-27.
11.5
Error Register
Error Register
7 6 5 4 3 2 1 0
CRC UNC 0 IDNF 0 ABRT
TK0NF
AMNF
Table 27 Error Register
This register contains status from the last command executed by the device, or a diagnostic code.
At the completion of any command except Execute Device Diagnostic, the contents of this register
are valid always even if ERR=0 in the Status Register.
Following a power on, a reset, or completion of an Execute Device Diagnostic command, this register
contains a diagnostic code. See “Table 31 Diagnostic Codes” on Page 51 for the definition.
Bit Definitions
ICRCE (CRC)
Interface CRC Error. CRC=1 indicates a CRC error has occurred on the data bus during a
Ultra-DMA transfer.
UNC
Uncorrectable Data Error. UNC=1 indicates an uncorrectable data error has been