User Manual

CompactFlash Memory Card Interface Description
3-20 CompactFlash
®
Memory Card Product Manual, Rev. 10.0 © 2002 SANDISK CORPORATION
For the Attribute Memory Read function, signals -REG and -OE must be active and -WE inactive during the cycle.
As in the Main Memory Read functions, the signals -CE1 and -CE2 control the even-byte and odd-byte address, but
only the even-byte data is valid during the Attribute Memory access. Refer to Table 3-11 below for signal states and
bus validity for the Attribute Memory function.
Table 3-16. Attribute Memory Function
Function Mode -REG -CE2 -CE1 A9 A0 -OE -WE D15-D8 D7-D0
Standby Mode X H H X X X X High Z High Z
Read Byte Access CIS ROM
(8 bits)
L H L L L L H High Z Even Byte
Write Byte Access CIS (8 bits)
(Invalid)
L H L L L H L Do not care Even Byte
Read Byte Access Configuration
(8 bits)
L H L H L L H High Z Even Byte
Write Byte Access Configuration
(8 bits)
L H L H L H L Do not care Even Byte
Read Word Access CIS (16 bits) L L L L X L H Not Valid Even Byte
Write Word Access CIS (16 bits)
(Invalid)
L L L L X H L Do not care Even Byte
Read Word Access Configuration
(16 bits)
L L L H X L H Not Valid Even Byte
Write Word Access Configuration
(16 bits)
L L L H X H L Do not care Even Byte
NOTE: The -CE signal or both the -OE signal and the -WE signal must be de-asserted between consecutive cycle
operations.
3.4.2. Configuration Option Register (Address 200h in Attribute Memory)
The Configuration Option Register is used to configure the cards interface, address decoding and interrupt and to
issue a soft reset to the CompactFlash Memory Card.
Operation D7 D6 D5 D4 D3 D2 D1 D0
R/W SRESET LevlREQ Conf5 Conf4 Conf3 Conf2 Conf1 Conf0
SRESET Soft Reset—Setting this bit to one (1), waiting the minimum reset width time and returning to zero (0)
places the CompactFlash Memory Card in the Reset state. Setting this bit to one (1) is equivalent to
assertion of the +RESET signal except that the SRESET bit is not cleared. Returning this bit to zero (0)
leaves the CompactFlash Memory Card in the same un-configured, Reset state as following power-up and
hardware reset. This bit is set to zero (0) by power-up and hardware reset. Using the PCMCIA Soft Reset
is considered a hard Reset by the ATA Commands. Contrast with Soft Reset in the Device Control
Register.
LevlREQ This bit is set to one (1) when Level Mode Interrupt is selected, and zero (0) when Pulse Mode is selected.
Set to zero (0) by Reset.
Conf5—Conf0 Configuration Index. Set to zero (0) by reset. It's used to select operation mode of the CompactFlash
Memory Card as shown below.
NOTE: Conf5 and Conf4 are reserved and must be written as zero (0).