at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 146

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

20.6.7
20.6.7.1
146
AT91SAM9G20 Preliminary
NAND Flash Support
External Bus Interface
Figure 20-5. CompactFlash Application Example
The External Bus Interface integrates circuitry that interfaces to NAND Flash devices.
The NAND Flash logic is driven by the Static Memory Controller on the NCS3 address space.
Programming the EBI_CS3A field in the EBI_CSA Register in the Chip Configuration User Inter-
face to the appropriate value enables the NAND Flash logic. For details on this register, refer to
the section “AT91SAM9G20 Bus Matrix”. Access to an external NAND Flash device is then
made by accessing the address space reserved to NCS3 (i.e., between 0x4000 0000 and
0x4FFF FFFF).
The NAND Flash Logic drives the read and write command signals of the SMC on the NANDOE
and NANDWE signals when the NCS3 signal is active. NANDOE and NANDWE are invalidated
as soon as the transfer address fails to lie in the NCS3 address space. See
147
troller (SMC)”.
for more information. For details on the waveforms, refer to the section “Static Memory Con-
NWR3/CFIOW
NWR1/CFIOR
NCS4/CFCS0
A25/CFRNW
NWE/CFWE
EBI
NOE/CFOE
A22/REG
CD (PIO)
D[15:0]
NWAIT
CFCE1
CFCE2
A[10:0]
DIR
/OE
/OE
CompactFlash Connector
D[15:0]
_CD1
_CD2
A[10:0]
_REG
_OE
_WE
_IORD
_IOWR
_CE1
_CE2
_WAIT
Figure 20-6 on page
6384B–ATARM–15-Dec-08