User Manual

CompactFlash Memory Card Interface Description
3-24 CompactFlash
®
Memory Card Product Manual, Rev. 10.0 © 2002 SANDISK CORPORATION
Table 3-23. Common Memory Function
Function Code -REG -CE2 -CE1 A0 -OE -WE D15-D8 D7-D0
Standby Mode X H H X X X High Z High Z
Byte Read Access (8 bits) H
H
H
H
L
L
L
H
L
L
H
H
High Z
High Z
Even-Byte
Odd-Byte
Byte Write Access (8 bits) H
H
H
H
L
L
L
H
H
H
L
L
Do not care
Do not care
Even-Byte
Odd-Byte
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 Do not care
3.7. True IDE Mode I/O Transfer Function
This section contains valuable information on the True IDE Mode I/O Transfer function.
3.7.1. True IDE Mode I/O Function
The CompactFlash Memory Card can be configured in a True IDE Mode of operation. This CompactFlash Card is
configured in this mode only when the -OE input signal is grounded by the host when power is applied to the card.
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 CompactFlash Memory Card while the host computer’s power is on will
reconfigure the CompactFlash Card to PC Card ATA mode from the original True IDE Mode. To configure
the CompactFlash Card in True IDE Mode, the 50-pin socket must be power cycled with the CompactFlash
Card inserted and -OE (output enable) grounded by the host.
Table 3-24 defines the function of the operations for the True IDE Mode.
Table 3-24. 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 Do not 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 Do not care Control In
Alt Status Read L H 6h L H High Z Status Out