(11)INITIALIZE DEVICE PARAMETERS (X'91')
The host system can set the number of sectors per track and the maximum head number (maximum head number is "number of heads minus 1") per cylinder with this command. Upon receipt of this command, the device sets the BSY bit of Status register and saves the parameters. Then the device clears the BSY bit and generates an interrupt.
When the SC register is specified to X'00', an ABORTED COMMAND error is posted. Other than X'00' is specified, this command terminates normally.
The parameters set by this command are retained even after reset or power save operation regardless of the setting of disabling the reverting to default setting.
In LBA mode
The device ignores the L bit specification and operates with the CHS mode specification. An accessible area of this command within head moving in the LBA mode is always within a default area. It is recommended that the host system refers the addressable user sectors (total number of sectors) in word 60 to 61 of the parameter information by the IDENTIFY DEVICE command.
At command issuance (I/O registers setting contents)
1F7H(CM) | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | |
|
|
|
|
|
|
|
|
| |
1F6H(DH) | × | × | × | DV |
|
| Max. head No. |
| |
|
|
|
|
|
|
|
|
|
|
1F5H(CH) |
|
|
|
| xx |
|
|
| |
1F4H(CL) |
|
|
|
| xx |
|
|
| |
1F3H(SN) |
|
|
|
| xx |
|
|
| |
1F2H(SC) |
|
| Number of sectors/track |
|
| ||||
1F1H(FR) |
|
|
|
| xx |
|
|
| |
|
|
|
|
|
|
|
|
|
|
At command completion (I/O registers contents to be read)
1F7H(ST) |
|
|
| Status information | |||
|
|
|
|
|
|
|
|
1F6H(DH) | × | × | × |
| DV |
| Max. head No. |
|
|
|
|
|
|
|
|
1F5H(CH) |
|
|
|
|
| xx | |
1F4H(CL) |
|
|
|
|
| xx | |
1F3H(SN) |
|
|
|
|
| xx | |
1F2H(SC) |
|
|
|
|
| xx | |
1F1H(ER) |
|
|
| Error Information | |||
|
|
|
|
|
|
|
|
(12)IDENTIFY DEVICE (X'EC')
The host system issues the IDENTIFY DEVICE command to read parameter information (512 bytes) from the device. Upon receipt of this command, the drive sets the BSY bit of Status register and sets required parameter information in the sector buffer. The device then sets the DRQ bit of the Status register, and generates an interrupt. After that, the host system reads the information out of the sector buffer. Table 5.5 shows the arrangements and values of the parameter words and the meaning in the buffer.
5 - 28 |
|
