Flexible memory controller (FMC)
RM0090
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commands) are issued using the timing parameters configured for SDRAM Bank 1 (TMRD,
TRAS and TXSR timings) in the FMC_SDTR1 register.
SDRAM controller write cycle
The SDRAM controller accepts single and burst write requests and translates them into
single memory accesses. In both cases, the SDRAM controller keeps track of the active row
for each bank to be able to perform consecutive write accesses to different banks (Multibank
ping-pong access).
Before performing any write access, the SDRAM bank write protection must be disabled by
clearing the WP bit in the FMC_SDCRx register.
Figure 476. Burst write SDRAM access waveforms
The SDRAM controller always checks the next access.
•
If the next access is in the same row or in another active row, the write operation is
carried out,
•
if the next access targets another row (not active), the SDRAM controller generates a
precharge command, activates the new row and initiates a write command.
SDRAM controller read cycle
The SDRAM controller accepts single and burst read requests and translates them into
single memory accesses. In both cases, the SDRAM controller keeps track of the active row
in each bank to be able to perform consecutive read accesses in different banks (Multibank
ping-pong access).
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