IBM DJSA-205, Specifications, Page: 113 / 211

Execution includes the transfer of one or more 512 byte (> 512 bytes on Write Long) sectors of data from
the host to the device.
1. The host writes any required parameters to the Features, Sector Count, Sector Number, Cylinder, and
Device/Head Registers.
2. The host writes the command code to the Command Register.
3. The device sets BSY = 1.
4. For each sector (or block) of data to be transferred:
a. The device sets BSY = 0 and DRQ = 1 when it is ready to receive a sector (or block).
b. The host writes one sector (or block) of data via the Data Register.
c. The device sets BSY = 1 after it has received the sector (or block).
d. When the device has finished processing the sector (or block), it sets BSY = 0, and interrupts the
host.
e. In response to the interrupt, the host reads the Status Register.
f. The device clears the interrupt in response to the Status Register being read.
5. For the Write Long command:
a. The device sets BSY = 0 and DRQ = 1 when it is ready to receive a sector.
b. The host writes one sector of data including ECC bytes via the Data Register.
c. The device sets BSY = 1 after it has received the sector.
d. After processing the sector of data the device sets BSY = 0 and interrupts the host.
e. In response to the interrupt, the host reads the Status Register.
f. The device clears the interrupt in response to the Status Register being read.
The Write Multiple command transfers one block of data for each interrupt. The other commands transfer
one sector of data for each interrupt.
If the device detects an invalid parameter, then it will abort the command by setting BSY = 0, ERR = 1,
ABT = 1, and interrupting the host.
If an uncorrectable error occurs, the device will set BSY = 0 and ERR = 1, store the error status in the
Error Register, and interrupt the host. The registers will contain the location of the sector in error. The
error location will be reported with CHS mode or LBA mode. The mode is decided by the mode select bit
(bit 6) of the Device/Head register on issuing the command.
All data transfers to the host through the Data Register are 16 bits. The ECC bytes are an exception
having only 8 bits.
12.3 Nondata commands
The following are examples of Nondata commands:
!
Check Power Mode
!
Enable/Disable Delayed Write
!
Execute Device Diagnostic
!
Flush Cache
!
Format Unit
!
Idle
!
Idle Immediate
Travelstar 32GH/30GT/20GN hard disk drive specifications
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