
28 COMPACTFLASH
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EPSON
S1C38000 TECHNICAL MANUAL
28 CompactFlash
28.1 Overview
The S1C38000 provides a 3.3V interface for a single CompactFlash (CF) card device. To interface
to a 5V CompactFlash device, external level shifting and isolation buffers are required. For both
3.3V and 5V devices, isolation buffers and transceivers must be used on the address bus and data
bus respectively. Two additional output signals to control the external buffers and transceivers are
provided: CFDEN# as the address and data enable for the address buffer and the data transceiver,
and CFDDIR as the data direction control for the data transceiver. These two output pins can be re-
configured to GPO pins if CompactFlash support is not needed. This re-configuration bit resides in
the GPIO Port registers.
Memory mode and I/O modes are supported; True IDE mode is not supported.
28.2 Register Descriptions
The default base address for the CF registers is F8000C00h. All non-reserved register bits default to
0 unless specified otherwise.
<Read>
1
Input-caused interrupt from CompactFlash
0
No interrupt (default)
<Write>
1
Clear interrupt bit
0
No change
bit 15
CFWP OUT
Negative interrupt on active high, memory mode write protect pin, CFWP1.
bit 14
CFREADY OUT
Negative interrupt on active high, memory mode ready pin, CFREADY1.
bits 13–12 CFBVD[2:1] OUT
Negative interrupt on active high, battery voltage detect pins, CFBVD[2:1]1.
bits 11–10 CFVS[2:1]# OUT
Positive interrupt on active low, voltage sense pins, CFVS[2:1]#2.
bits 9–8
CFCD[2:1]# OUT
Positive interrupt on active low, card detect pins, CFCD[2:1]#3.
bit 7
CFWP IN
Positive interrupt on active high, memory mode write protect pin, CFWP1.
bit 6
CFREADY IN
Positive interrupt on active high, memory mode ready pin, CFREADY1.
bits 5–4
CFBVD[2:1] IN
Positive interrupt on active high, battery voltage detect pins, CFBVD[2:1]1.
CompactFlash Input Interrupt Status/Clear Register
CF[00h]
Default = 0000 0000h
Read/Write
n/a
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
CFWP
Inactive
(Input)
CFREADY
Inactive
(Input)
CFBVD2
Inactive
(Input)
CFBVD1
Inactive
(Input)
CFVS2#
Inactive
(Input)
CFVS1#
Inactive
(Input)
CFCD2#
High
(Input)
CFCD1#
High
(Input)
CFWP
Active
(Input)
CFREADY
Active
(Input)
CFBVD2
Active
(Input)
CFBVD1
Active
(Input)
CFVS2#
Active
(Input)
CFVS1#
Active
(Input)
CFCD2#
Low
(Input)
CFCD1#
Low
(Input)
15
14
13
12
11
10
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