Interface Description SanDisk CompactFlash Card OEM Product Manual
Table 3-4 Signal Description
Signal Name Dir. Pin Description
-IOWR
(PC Card I/O Mode)
(True IDE Mode)
The I/O write strobe pulse is used to clock I/O
data on the Card Data bus into the card
controller registers when the card is configured
to use the I/O interface.
The clocking will occur on the negative to
positive edge of the signal (trailing edge).
-OE
(PC Card Memory Mode)
-OE
(PC Card I/O Mode)
-ATA SEL
(True IDE Mode)
I 9 This is an output enable strobe generated by
the host interface. It is used to read data from
the card in Memory Mode and to read the CIS
and configuration registers.
In PC Card I/O Mode, this signal is used to read
the CIS and configuration registers.
To enable True IDE Mode this input should be
grounded by the host.
RDY/-BSY
(PC Card Memory Mode)
-IREQ
(PC Card I/O Mode)
INTRQ
(True IDE Mode)
O 37 In Memory Mode, this signal is set high when
the card is ready to accept a new data transfer
operation and held low when the card is busy.
The host memory card socket must provide a
pull-up resistor.
At power up and at reset, the RDY/-BSY signal
is held low (busy) until the card has completed
its power up or reset function. No access of any
type should be made to the card during this
time. The RDY/-BSY signal is held high
(disabled from being busy) whenever the
following condition is true: The card has been
powered up with +RESET continuously
disconnected or asserted.
I/O Operation–After the card has been
configured for I/O operation, this signal is used
as an interrupt request. This line is strobed low
to generate a pulse mode interrupt or held low
for a level mode interrupt.
In True IDE Mode, this signal is the active high
Interrupt Request to the host.
-REG
(PC Card Memory Mode)
-REG
(PC Card I/O Mode)
I 44 This Attribute Memory Select signal is used
during memory cycles to distinguish between
Common Memory and Register (Attribute)
Memory accesses: High for common memory,
and low for attribute memory.
The signal must also be active (low) during I/O
cycles when the I/O address is on the bus.
02/07, Rev. 12.0 3-6 © 2007 SanDisk Corporation