AT91SAM9G45PRE Datasheet, PDF (170/1218 Pages) ATMEL Corporation – DDR2 Controller 4-bank DDR2/LPDDR, SDRAM/LPSDR

Figure 20-6. CompactFlash Read/Write Control Signals
External Bus Interface
SMC
A23
1
1
0
1
A22
NRD_NOE
NWR0_NWE
CompactFlash Logic
0
0
1
1
0
1
1
1
CFOE
CFWE
CFIOR
CFIOW
Table 20-8. CompactFlash Mode Selection
Mode Base Address
CFOE
Attribute Memory
Common Memory
NRD
I/O Mode
1
True IDE Mode
0
CFWE
NWR0_NWE
1
1
CFIOR
1
NRD
NRD
CFIOW
1
NWR0_NWE
NWR0_NWE
Multiplexing of CompactFlash Signals on EBI Pins
Table 20-9 on page 170 and Table 20-10 on page 171 illustrate the multiplexing of the Compact-
Flash logic signals with other EBI signals on the EBI pins. The EBI pins in Table 20-9 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 20-10 on page 171 remain shared between all memory areas when the
corresponding CompactFlash interface is enabled (EBI_CS4A = 1 and/or EBI_CS5A = 1).
Table 20-9. Dedicated CompactFlash Interface Multiplexing
CompactFlash Signals
Pins
CS4A = 1
CS5A = 1
NCS4/CFCS0
CFCS0
NCS5/CFCS1
CFCS1
CS4A = 0
NCS4
EBI Signals
CS5A = 0
NCS5
170 AT91SAM9G45
6438F–ATARM–21-Jun-10