Flexible static memory controller (FSMC)
RM0365
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DocID025202 Rev 7
14.5.3
General timing rules
Signals synchronization
•
All controller output signals change on the rising edge of the internal clock (HCLK)
•
In synchronous mode (read or write), all output signals change on the rising edge of
HCLK. Whatever the CLKDIV value, all outputs change as follows:
–
NOEL/NWEL/ NEL/NADVL/ NADVH /NBLL/ Address valid outputs change on the
falling edge of FMC_CLK clock.
–
NOEH/ NWEH / NEH/ NOEH/NBLH/ Address invalid outputs change on the rising
edge of FMC_CLK clock.
PSRAM
(multiplexed
I/Os and non-
multiplexed
I/Os)
Asynchronous
R 8 16 Y
-
Asynchronous W
8
16
Y
Use
of byte lanes NBL[1:0]
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
-
Synchronous
W
8
16
Y
Use of byte lanes NBL[1:0]
Synchronous
W
16/32
16
Y
-
SRAM and
ROM
Asynchronous
R
8 / 16
16
Y
-
Asynchronous W
8 / 16
16
Y
Use of byte lanes NBL[1:0]
Asynchronous
R
32
16
Y
Split into 2 FMC accesses
Asynchronous W
32
16
Y
Split into 2 FMC accesses
Use of byte lanes NBL[1:0]
Table 52. NOR Flash/PSRAM: Example of supported memories and
transactions (continued)
Device
Mode
R/W
AHB
data
size
Memory
data size
Allowed/
not
allowed
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