Instruction Manual
503 Series Industrial Grade CompactFlash Card Product Manual v2.1Cactus Technologies
®
25
Common Memory Transfer Function
3.6.
True IDE Mode I/O Transfer Function
3.7.
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 ReadAccess
(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
The Common Memory transfer to or from the CompactFlash card can be either 8 or 16 bits. The
CompactFlash cards permit both 8- and 16-bit accesses to all of its Common addresses (refer to
Table 3-17).
The CompactFlash card can be congured in a True IDE Mode of operation. This CompactFlash card
is congured in this mode only when the -OE input signal is grounded by the host when power is
applied to the card. In True IDE Mode, the CF Card protocol and conguration are disabled and only
I/O operations to the Task File and Data Register are allowed. In addition, No Memory or Attribute
Registers are accessible to the host.
NOTE: Removing and reinserting the CompactFlash Memory Card while the host computer’s power is on will recongure the
CompactFlash Card to PC Card ATA mode from the original True IDE Mode. To congure 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 3-18 denes the function of the operations for the True IDE Mode.
Table 3-17. Common Memory Function