User guide

203 Series Industrial Grade 2.5" FlashDrive Product Manual v2.0Cactus Technologies
®
34
Interrupts are generated when DRQ is set at the beginning of each block or partial block. The error
reporting is the same as that on a Read Sector(s) Command. This command reads from 1 to 256
sectors as specied in the Sector Count register. A sector count of 0 requests 256 sectors. The
transfer begins at the sector specied in the Sector Number Register.
At command completion, the Command Block Registers contain the cylinder, head and sector
number of the last sector read. If an error occurs, the read terminates at the sector where the error
occurred. The Command Block Registers contain the cylinder, head and sector number of the sector
where the error occurred. The awed data is pending in the sector buer.
Subsequent blocks or partial blocks are transferred only if the error was a correctable data error. All
other errors cause the command to stop after transfer of the block that contained the error.
5.1.11. Read Long Sector-22H, 23H
Bit -> 7 6 5 4 3 2 1 0
Command (7)
22H or 23H
C/D/H (6)
1 LBA 1 Drive Head (LBA 27-24)
Cyl High (5)
Cylinder High (LBA 23-16)
Cyl Low (4)
Cylinder Low (LBA 15-8)
Sec Num (3)
Sector Number (LBA 7-0)
Sec Cnt (2)
X
Feature (1)
X
Table 5-22. Read Long Sector
The Read Long command in Table 5-22 performs similarly to the Read Sector(s) command except
that it returns 516 bytes of data instead of 512 bytes. During a Read Long command, the drive does
not check the ECC bytes to determine if there has been a data error. Only single sector read long
operations are supported. The transfer consists of 512 bytes of data transferred in word mode
followed by 4 bytes of random data transferred in byte mode. Random data is returned instead of
ECC bytes because of the nature of the ECC system used. This command has the same protocol as
the Read Sector(s) command.
5.1.12. Read Sector(s)-20H, 21H
The Read Sector(s) command in Table 5-23 reads from 1 to 256 sectors as specied in the Sector
Count register. A sector count of 0 requests 256 sectors. The transfer begins at the sector specied
in the Sector Number Register. When this command is issued and after each sector of data (except
the last one) has been read by the host, the drive sets BSY, puts the sector of data in the buer, sets
DRQ, clears BSY, and generates an interrupt. The host then reads the 512 bytes of data from the
buer.
At command completion, the Command Block Registers contain the cylinder, head and sector
number of the last sector read. If an error occurs, the read terminates at the sector where the error
occurred. The Command Block Registers contain the cylinder, head, and sector number of the sector
where the error occurred. The awed data is pending in the sector buer.