
RM0008
Flexible static memory controller (FSMC)
Doc ID 13902 Rev 12
527/1096
21.6.1
External memory interface signals
The following tables list the signals that are typically used to interface NAND Flash and PC
Card.
Caution:
When using a PC Card or a CompactFlash in I/O mode, the NIOS16 input pin must remain
at ground level during the whole operation, otherwise the FSMC may not operate properly.
This means that the NIOS16 input pin must
not
be connected to the card, but directly to
ground (only 16-bit accesses are allowed).
Note:
Prefix “N”. specifies the associated signal as active low.
8-bit NAND Flash
t
There is no theoretical capacity limitation as the FSMC can manage as many address
cycles as needed.
Table 128.
Programmable NAND/PC Card access parameters
Parameter
Function
Access mode
Unit
Min. Max.
Memory setup
time
Number of clock cycles (HCLK)
to set up the address before the
command assertion
Read/Write
AHB clock cycle
(HCLK)
1 256
Memory wait
Minimum duration (HCLK clock
cycles) of the command assertion
Read/Write
AHB clock cycle
(HCLK)
2
256
Memory hold
Number of clock cycles (HCLK)
to hold the address (and the data
in case of a write access) after
the command de-assertion
Read/Write
AHB clock cycle
(HCLK)
1 255
Memory
databus high-Z
Number of clock cycles (HCLK)
during which the databus is kept
in high-Z state after the start of a
write access
Write
AHB clock cycle
(HCLK)
0 255
Table 129.
8-bit NAND Flash
FSMC signal name
I/O
Function
A[17]
O
NAND Flash address latch enable (ALE) signal
A[16]
O
NAND Flash command latch enable (CLE) signal
D[7:0]
I/O
8-bit multiplexed, bidirectional address/data bus
NCE[x]
O
Chip select, x = 2, 3
NOE(= NRE)
O
Output enable (memory signal name: read enable, NRE)
NWE
O Write
enable
NWAIT/INT[3:2]
I
NAND Flash ready/busy input signal to the FSMC