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RM0365
Flexible static memory controller (FSMC)
286
The maximum capacity is 512 Mbits (26 address lines).
14.5.2
Supported memories and transactions
below shows an example of the supported devices, access modes and
transactions when the memory data bus is 16-bit wide for NOR Flash memory, PSRAM and
SRAM. The transactions not allowed (or not supported) by the FMC are shown in gray in
this example.
AD[15:0] I/O
16-bit multiplexed, bidirectional address/data bus (the 16-bit address
A[15:0] and data D[15:0] are multiplexed on the databus)
NE[x]
O
Chip Select, x = 1..4 (called NCE by PSRAM (Cellular RAM i.e.
CRAM))
NOE
O Output
enable
NWE
O Write
enable
NL(= NADV)
O
Address valid PSRAM input (memory signal name: NADV)
NWAIT
I
PSRAM wait input signal to the FMC
NBL[1:0] O
Byte lane output. Byte 0 and Byte 1 control (upper and lower byte
enable)
Table 51.
16-Bit
multiplexed I/O PSRAM (continued)
FMC signal name
I/O
Function
Table 52. NOR Flash/PSRAM: Example of supported memories and
transactions
Device
Mode
R/W
AHB
data
size
Memory
data size
Allowed/
not
allowed
Comments
NOR Flash
(muxed I/Os
and nonmuxed
I/Os)
Asynchronous
R 8 16 Y
-
Asynchronous W
8
16
N
-
Asynchronous
R 16 16
Y
-
Asynchronous
W 16 16
Y
-
Asynchronous
R
32
16
Y
Split into 2 FMC accesses
Asynchronous W
32
16
Y
Split into 2 FMC accesses
Asynchronous
page
R
-
16
N
Mode is not supported
Synchronous
R
8
16
N
-
Synchronous R 16
16
Y
-
Synchronous R 32
16
Y
-