9 true ide mode i/o transfer function – Transcend Information Transcend CF 80X TS32M~1GCF80 User Manual
Page 33
T
T
T
S
S
S
3
3
3
2
2
2
M
M
M
~
~
~
1
1
1
G
G
G
C
C
C
F
F
F
8
8
8
0
0
0
80X CompactFlash Card
Transcend Information Inc.
V1.1
33
port is addressed, the signal -IOIS16 is asserted by the CompactFlash Storage. Otherwise, the -IOIS16 signal
is de-asserted. When a 16 bit transfer is attempted, and the -IOIS16 signal is not asserted by the CompactFlash
Storage, the system shall generate a pair of 8 bit references to access the word‘s even byte and odd byte. The
CompactFlash Storage Card permits both 8 and 16 bit accesses to all of its I/O addresses, so -IOIS16 is
asserted for all addresses to which the CompactFlash Storage responds. The CompactFlash Storage Card may
request the host to extend the length of an input cycle until data is ready by asserting the -WAIT signal at the
start of the cycle.
Function Code
-REG -CE2 -CE1
A0
-IORD
-IOWR
D15-D8
D7-D0
Standby Mode
X
H
H
X
X
X
High Z
High Z
Byte Input Access (8 bits)
L
L
H
H
L
L
L
H
L
L
H
H
High Z
High Z
Even-Byte
Odd-Byte
Byte Output Access (8 bits)
L
L
H
H
L
L
L
H
H
H
L
L
Don’t Care
Don’t Care
Even-Byte
Odd-Byte
Word Input Access (16 bits)
L
L
L
L
L
H
Odd-Byte
Even-Byte
Word Output Access (16 bits)
L
L
L
L
H
L
Odd-Byte
Even-Byte
I/O Read Inhibit
H
X
X
X
L
H
Don’t Care
Don’t Care
I/O Write Inhibit
H
X
X
X
H
L
High Z
High Z
High Byte Input Only (8 bits)
L
L
H
X
L
H
Odd-Byte
High Z
High Byte Output Only (8 bits)
L
L
H
X
H
L
Odd-Byte
Don’t Care
4.8 Common Memory Transfer Function
The Common Memory transfer to or from the CompactFlash Storage can be either 8 or 16 bits.
Table: 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
Don’t Care
Don’t 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
Don’t Care
4.9 True IDE Mode I/O Transfer Function
Table: PCMCIA Mode I/O Function