6 true ide mode i/o transfer function – SanDisk CompactFlash Extreme III User Manual
Page 44
Interface Description
SanDisk CompactFlash Card OEM Product Manual
Table 3-22
Common Memory Function
Function Code
-REG
-CE2
-CE1
A0
-OE
-WE
D15-D8
D7-D0
Word Read Access
(16 bits)
H
L
L
X
L
H
Odd Byte
Even Byte
Word Write Access
(16 bits)
H
L
L
X
H
L
Odd Byte
Even Byte
Odd Byte Read Only
(8 bits)
H
L
H
X
L
H
Odd Byte
High Z
Odd Byte Write Only
(8 bits)
H
L
H
X
H
L
Odd Byte
Don’t Care
3.6
True IDE Mode I/O Transfer Function
This section contains valuable information on the True IDE Mode I/O Transfer function.
3.6.1
True IDE Mode I/O Function
SanDisk CompactFlash Memory cards can be configured in a True IDE Mode of operation.
Cards are configured in this mode only when the -OE input signal is grounded by the host
when power is applied to the cards. In this True IDE Mode, the PCMCIA protocol and
configuration are disabled and only I/O operations to the Task File and Data Register are
allowed. In this mode, no Memory or Attribute registers are accessible to the host.
CompactFlash cards permit 8-bit data accesses if the user issues a Set Feature Command to put
the device in 8-bit Mode.
NOTE
: Removing and reinserting the card while the host computer's power
is on will reconfigure it to PC Card ATA mode from the original True
IDE Mode. To configure the card in True IDE Mode, the 50-pin
socket must be power cycled with the card inserted and -OE (output
enable) grounded by the host.
Table 3-23 defines the function of the operations for the True IDE Mode.
Table 3-23
IDE Mode I/O Function
Function Code
-CE2
-CE1
A0
-IORD
-IOWR
D15-D8
D7-D0
Invalid Mode
L
L
X
X
X
High Z
High Z
Standby Mode
H
H
X
X
X
High Z
High Z
Task File Write
H
L
1.7h
H
L
Don’t care
Data In
Task File Read
H
L
1-7h
L
H
High Z
Data Out
Data Register Write
H
L
0
H
L
Odd Byte in
Even Byte In
Data Register Read
H
L
0
L
H
Odd Byte Out
Even Byte Out
Control Register Write
L
H
6h
H
L
Don’t Care
Control In
Alt Status Read
L
H
6h
L
H
High Z
Status Out
02/07, Rev. 12.0
3-26
© 2007 SanDisk Corporation