Rainbow Electronics AT91CAP9S250A - Manual (Page 153)

153
6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
Figure 21-3. CompactFlash Read/Write Control Signals
21.5.8.4 Multiplexing of CompactFlash Signals on EBI Pins
Table 21-7 on page 153 and Table 21-8 on page 154 illustrate the multiplexing of the Com-
pactFlash logic signals with other EBI signals on the EBI pins. The EBI pins in Table 21-7 are
strictly dedicated to the CompactFlash interface as soon as the EBI_CS4A and/or EBI_CS5A
field of the EBI_CSA Register
in the Chip Configuration User Interface is set. These pins must
not be used to drive any other memory devices.
The EBI pins in Table 21-8 on page 154 remain shared between all memory areas when the
corresponding CompactFlash interface is enabled (EBI_CS4A = 1 and/or EBI_CS5A = 1).
SMC
NRD_NOE
NWR0_NWE
A23
CFIOR
CFIOW
CFOE
CFWE
1
1
CompactFlash Logic
External Bus Interface
1
1
1
0
A22
1
0
1
0
1
0
Table 21-6. CompactFlash Mode Selection
Mode Base Address CFOE CFWE CFIOR CFIOW
Attribute Memory
Common Memory
NRD NWR0_NWE 1 1
I/O Mode 1 1 NRD NWR0_NWE
True IDE Mode 0 1 NRD NWR0_NWE
Table 21-7. Dedicated CompactFlash Interface Multiplexing
Pins
CompactFlash Signals EBI Signals
EBI_CS4A = 1 EBI_CS5A = 1 EBI_CS4A = 0 EBI_CS5A = 0
NCS4/CFCS0 CFCS0 NCS4
NCS5/CFCS1 CFCS1 NCS5