User's Manual

T
T
T
S
S
S
2
2
2
G
G
G
~
~
~
8
8
8
G
G
G
C
C
C
F
F
F
2
2
2
6
6
6
6
6
6
266X CompactFlash Card
Transcend Information Inc.
49
Bit 3 (HS3): when operating in the Cylinder, Head, Sector mode, this is bit 3 of the head number. It is Bit
27 in the Logical Block Address mode.
Bit 2 (HS2): when operating in the Cylinder, Head, Sector mode, this is bit 2 of the head number. It is Bit
26 in the Logical Block Address mode.
Bit 1 (HS1): when operating in the Cylinder, Head, Sector mode, this is bit 1 of the head number. It is Bit
25 in the Logical Block Address mode.
Bit 0 (HS0): when operating in the Cylinder, Head, Sector mode, this is bit 0 of the head number. It is Bit
24 in the Logical Block Address mode.
¾ Status & Alternate Status Registers (Address 1F7h[177h]&3F6h[376h]; Offsets 7 & Eh)
These registers return the CompactFlash Storage Card status when read by the host. Reading
the Status register does clear a pending interrupt while reading the Auxiliary Status register does
not. The status bits are described as follows:
Bit 7 (BUSY): the busy bit is set when the CompactFlash Storage Card has access to the command buffer
and registers and the host is locked out from accessing the command register and buffer. No other bits
in this register are valid when this bit is set to a 1. During the data transfer of DMA commands, the
Card shall not assert DMARQ unless either the BUSY bit, the DRQ bit, or both are set to one.
Bit 6 (RDY): RDY indicates whether the device is capable of performing CompactFlash Storage Card
operations. This bit is cleared at power up and remains cleared until the CompactFlash Storage Card
is ready to accept a command.
Bit 5 (DWF): This bit, if set, indicates a write fault has occurred.
Bit 4 (DSC): This bit is set when the CompactFlash Storage Card is ready.
Bit 3 (DRQ): The Data Request is set when the CompactFlash Storage Card requires that information be
transferred either to or from the host through the Data register. During the data transfer of DMA
commands, the Card shall not assert DMARQ unless either the BUSY bit, the DRQ bit, or both are set
to one.
Bit 2 (CORR): This bit is set when a Correctable data error has been encountered and the data has been
corrected. This condition does not terminate a multi-sector read operation.
Bit 1 (IDX): This bit is always set to 0.
Bit 0 (ERR): This bit is set when the previous command has ended in some type of error. The bits in the
Error register contain additional information describing the error. It is recommended that media access
commands (such as Read Sectors and Write Sectors) that end with an error condition should have the
address of the first sector in error in the command block registers.