MD1050-DCC M-Systems Inc., MD1050-DCC Datasheet - Page 12
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MD1050-DCC
Manufacturer Part Number
MD1050-DCC
Description
Diskonchip Ide Pro Data Sheet
Manufacturer
M-Systems Inc.
Datasheet
1.MD1050-DCC.pdf
(53 pages)
4. D
The Command Block registers are used for sending commands to the device or posting status from
the device. These registers include the Cylinder High, Cylinder Low, Device/Head, Sector Count,
Sector Number, Command, Status, Features, Error, and Data registers. The Control Block registers
are used for device control and to post alternate status. These registers include the Device Control
and Alternate Status registers.
4.1
This register contains the device status. The contents of this register are updated to reflect the
current state of the device and the progress of any command being executed by the device. When
BSY=0, the other bits in this register are valid. When BSY=1, other bits in this register are not
valid. The contents of this register and all other Command Block Registers are not valid when the
device is in Sleep mode.
11
Bit No.
Bit 7
BSY
0
1
2
3
4
5
6
7
ESCRIPTION OF
Status Register (Read)
ERR. When set, indicates that an error has occurred during the previous command execution.
The bits in the Error register indicate the cause. See Section 5.2 for an overview of error codes.
IDX (Index). Index is vendor specific.
CORR (Corrected Data). Indicates a correctable data error. The definition of what constitutes a
correctable error is vendor specific.
DRQ (Data Request). When set, indicates that the device is ready to transfer a word or byte of
data between the host and the device.
DSC (Drive Seek Complete). When set, indicates that the requested sector was found.
DF (Device Fault). Indicates that a device fault error has been detected.
DRDY (Device Ready). Indicates whether the device is capable of performing drive operations
(commands). This bit is cleared at power up and remains cleared until the drive is ready to
accept a command.
BSY (Busy). Set whenever the device has control of the Command Block registers. When
BSY=1, the commands written to this register will be ignored by the device.
DRDY
Bit 6
C
OMMAND
Bit 5
DF
DiskOnChip IDE Pro Data Sheet, Rev. 1.5
B
LOCK
Bit 4
DSC
R
Description
EGISTERS
Bit 3
DRQ
CORR
Bit 2
Bit 1
IDX
91-SR-012-01-8L
Bit 0
ERR