at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 147

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

20.6.7.2
6384B–ATARM–15-Dec-08
NAND Flash Signals
Figure 20-6. NAND Flash Signal Multiplexing on EBI Pins
The address latch enable and command latch enable signals on the NAND Flash device are
driven by address bits A22 and A21 of the EBI address bus. The command, address or data
words on the data bus of the NAND Flash device are distinguished by using their address within
the NCSx address space. The chip enable (CE) signal of the device and the ready/busy (R/B)
signals are connected to PIO lines. The CE signal then remains asserted even when NCSx is
not selected, preventing the device from returning to standby mode.
Figure 20-7. NAND Flash Application Example
Note:
The External Bus Interface is also able to support 16-bit devices.
SMC
EBI
NWR0_NWE
PIO
PIO
NRD_NOE
NCSx
NCSx/NANDCS
D[7:0]
A[22:21]
NANDWE
NANDOE
Not Connected
AT91SAM9G20 Preliminary
NAND Flash Logic
NANDOE
NANDWE
CE
R/B
ALE
CLE
NOE
NWE
AD[7:0]
NAND Flash
NANDOE
NANDWE
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