Command Descriptions - Fujitsu MHW2120BK Maintenance Manual

Interface

5.3.2 Command descriptions

The contents of the shadow block registers to be necessary for issuing a command
and the example indication of the shadow block registers at command completion
are shown as following in this subsection.
Example: READ SECTOR (S)
At command issuance
(Shadow Block Registers setting contents)
Bit 7 6
CM 0 0
DH x L
CH EXP
Start cylinder address
CH
[MSB] / LBA (23-16)
CL EXP
Start cylinder address
CL
SN EXP
SN Start sector No. / LBA (7-0)
SC EXP Transfer sector count (15-8)
SC Transfer sector count (7-0)
FR EXP
FR
CH (EXP):
CL (EXP):
CM:
DH:
ER:
FR (EXP):
L:
SN (EXP):
SC (EXP):
ST:
x, xx:
Note:
5-30
5 4 3 2 1 0
1 0 0 0 0 0
x x HD No./LBA
LBA (47-40)
LBA (39-32)
[LSB] / LBA (15-8)
LBA (31-24)
xx
xx
Cylinder High Field (EXP)
Cylinder Low Field (EXP)
Command Field
Device/Head Field
Error Field
Features Field (EXP)
LBA (Logical Block Address) setting bit
Sector Number Field (EXP)
Sector Count Field (EXP)
Status Field
Don't care (setting is not necessary).
1. When the L bit is specified to 1, the lower 4 bits of the DH
field and all bits of the CH field, CL and SN fields indicate
the LBA bits (bits of the DH filed are the MSB (most
significant bit) and bits of the SN field are the LSB (least
significant bit).
2. At error occurrence, the SC field indicates the remaining sector
count of data transfer.
3. Bit indication is omitted in each command description.
At command completion
(Shadow Block Registers to be read)
Bit 7 6 5
ST Status information
DH x L x
CH EXP LBA (47-40)
End cylinder address
CH
[MSB] / LBA (23-16)
CL EXP LBA (39-32)
End cylinder address
CL
[LSB] / LBA (15-8)
SN EXP LBA (31-24)
SN End sector No. / LBA (7-0)
SC EXP
SC
ER Error information
4 3 2 1 0
x HD No./LBA
X '00'
X '00'
C141-E261