DocID018909 Rev 11
RM0090
Flexible static memory controller (FSMC)
1588
36.5.3
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 FSMC_CLK clock.
–
NOEH/ NWEH / NEH/ NOEH/NBLH/ Address invalid outputs change on the rising
edge of FSMC_CLK clock.
PSRAM
(multiplexed
I/Os and
nonmultiplexed
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 FSMC accesses
Asynchronous W
32
16
Y
Split into 2 FSMC 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 FSMC accesses
Asynchronous W 32
16
Y
Split into 2 FSMC
accesses.
Use of byte lanes NBL[1:0]
Table 220. NOR Flash/PSRAM controller: example of supported memories
and transactions (continued)
Device
Mode
R/W
AHB
data
size
Memory
data size
Allowed/
not
allowed
Comments