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STM32H723 - Problem with Serial RAM in memory mapped mode

MDell.1
Associate II

Hi everyone,

I’m testing a 32Mb serial QUAD SPI RAM (ISSI – ISS66WVS4M8) with the nucleo – H723ZG development board.

It works fine if I use all the QUAD SPI commands but my need is to use it in memory mapped mode.

When i use the memory mapped mode configuration I notice a problem in the write phase.

The test that I’m doing consists in writing a sector of the memory and then reading it, checking that both operations are fine.

So, after having set the memory mapped configuration, I try to write with a for cycle 128 values inside the memory.

Here is the strange thing: if these 128 values that I try to write are a “uint64_t�?  type the write operation works fine.

But if I use “uint8_t�? or uint32_t�?  type, write operation don’t work and some of the values read in the memory are not correct.

I also have noticed that with the 64bit variable, the “CHIP SELECT�? signal is correctly set low at the beginning of the operation and set high just at the end of the whole operation, while with the 32 o 8 bit variable CS goes low and high several times.

Do you have any suggesions? I attach the code

Best Regards,

Mattia

14 REPLIES 14

Good question... I don't have time for bit-by-bit scope debugging of the quad signal.

So sometimes I can't tell if the writing or the reading is the problem.

So I will switch to HyperBus / Octo RAM anyway.

Alex - APMemory
Senior II

Ok that's seems good to move to OPI.

You have a wide range of option from 64Mb up to 512Mb 1.8V or 3V

OPI equivalent product of the QSPI product you have tested: APS6408L-OBM-BA

0693W00000YAGuCQAX.pngFor reference and proto:

https://eu.mouser.com/c/semiconductors/memory-ics/dram/?package%20%2F%20case=BGA-24&tradename=APMemory

Alex

I have a question regarding the AP memory, APS6408L, I am trying to interface it with STM32U585 (actually using a B-U585I-IOT02A dev kit). I am using memory mapped mode for both read and write.

According to the datasheet, page size is 1Kb and I saw this additional information in the datasheet,

"7.2 Burst Type & Length
Read and write operations are default Hybrid Wrap 32 mode. Other burst lengths of 16, 32, 64 or 1K bytes in
standard or Hybrid wrap modes are register configurable(see Table 20). The device also includes command for
Linear Bursting. Bursts can start on any even address. Write burst length has a minimum of 2 bytes. Read has no
minimum length. Both write and read have no restriction on maximum burst length as long as tCEM is met."

 

Does this mean, it is possible to write datalength of more than 1Kb at a time in memory-mapped mode? Does the page size restrict the maximum size of data that can be written at once? I am using memcpy command to copy the data.

 

Thanks in advance.

 

Rikesh

 

Just updating the STM32 - IoT RAM (QSPI, Octal and  Hexa RAM) support overview

AlexAPMemory_0-1713374986714.png

AP MEMORY - STMicroelectronics

Updated AP Memory IoT RAM (QSPI, OPI & HPI PSRAM) overview with latest STM32 MCU

AlexAPMemory_1-1713378085336.png