STMicroelectronics STM32F405

Flexible static memory controller (FSMC) RM0090
1556/1731 DocID018909 Rev 11
1. DATAST in FSMC_BTRx register) Memory asserts the WAIT signal aligned to
NOE/NWE which toggles:
2. Memory asserts the WAIT signal aligned to NEx (or NOE/NWE not toggling):
if
then
otherwise
where max_wait_assertion_time is the maximum time taken by the memory to assert
the WAIT signal once NEx/NOE/NWE is low.
Figure 447 and Figure 448 show the number of HCLK clock cycles that are added to the
memory access after WAIT is released by the asynchronous memory (independently of the
above cases).
Figure 447. Asynchronous wait during a read access
1. NWAIT polarity depends on WAITPOL bit setting in FSMC_BCRx register.
DATAST 4 HCLK×()max_wait_assertion_time+≥
max_wait_assertion_time address_phase hold_phase+>
DATAST 4 HCLK×()max_wait_assertion_time address_phase– hold_phase–()+≥
DATAST 4 HCLK×≥
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./%
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-EMORYTRANSACTION
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$;=
.%X
DATADRIVEN
BYMEMORY
ADDRESSPHASE
DONTCARE
DATASETUPPHASE
DONTCARE