How to configure external memory in NUCLEO-H745ZI

[ggowd.1]

Hello Team,

I want to add external memory to NUCLEO-H745ZI board. In that board i have configured 2SPI, Ethernet (without RTIOS) and Timmer for that I need huge memory. This there any configuration or steps to add external memory to board.

Best Regards,
Gagan Gowda
 

[Pavel A.]

Unfortunately adding external RAM to Nucleo boards is too hard. For a fast external RAM you need a more expensive Discovery type board.  If you need storage for data files, use a standard SD-card (gigabytes of storage) or SPI/QSPI flash. The Discovery boards have external flash and SD as well.

For the application features you've mentioned (Ethernet, SPI, timers without RTOS) the H745 has a plenty of internal memories. You don't need any external memories for that alone.

[Tesla DeLorean]

Check some of the DISCO/DK boards as these have SDRAM and QSPI NOR FLASH

Adding SDRAM or large parallel RAM is non-trivial, check the part data sheet and data manual to see if you have available pins to implement anything. QSPI NOR FLASH is generally viable via 6 pins on the connector headers.

[SofLit]

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I want to add external memory to NUCLEO-H745ZI board. In that board i have configured 2SPI, Ethernet (without RTIOS) and Timmer for that I need huge memory.

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Just wanted to understand: why you need to add an external huge memory for just 2xSPI, Ethernet and a timer? 

The MCU could do that natively (2MB of Flash/1MB of RAM) without adding any external memory unless you have another data to store and you didn't mention it.

Meanwhile, as said above, adding external memory, mainly high speed memory such as SDRAM/QSPI,  is hard and restrictive because of the timing constraints and some layout requirements unless you need a low perf with memory access at low speed.

[ggowd.1]

Hi SofLit,

I have integrated Nucleo-h745zi Board with AD7768 4-Channel. For every 0.25msec we are collecting 32k data when it comes to 1 sec data size should 126000 data (32-bit). we need 4 arrays of 126000 size (32 bit), so we need huge memory to store data. If not possible to add external memory, then could you suggest board compatible for the above requirement.

PFA of warning memory where a single array of 126000 size is used.  

Best Regards,
Gagan Gowda

[MM..1]

Are you sure about requirments 1s buffer.? In normal situations buffers for ADC is around 5-50ms.

[ggowd.1]

Hi MM..1,

I am using EVAL- AD7768-4MCZ Board is sending 32k data at every 0.25ms to NUCLEO-H745ZI Board using SPI_DMA in (circular mode) function when it completes 126000 data automatically it resets array. So, for that we need 4 arrays of 126000 size (32 bit),

Enclosed image of AD7768 with NUCLEO-H745ZI.

Best Regards,
Gagan Gowda 

[LCE]

Before playing with external RAM, I'd think about other strategies of how to record and handle data and buffers.

Maybe reduce initial buffers size, but use more buffers, use DMA's double buffering, send data more frequently.

Or is the 1 second storage an absolute must? If yes, why? Maybe check if the data sink (PC?) can run more smoothly to ensure buffers can be cleared often enough.

[SofLit]

Hello,

It depends on if you need an STM32H7 device or you can use another series.

For STM32H7:

I can suggest STM32H745I-DISCO or STM32H747I-DISCO or STM32H750B-DK. 

For F7:

I can suggest STM32F769I-Discovery or STM32746G-Discovery or STM32F7508-DISCO or STM32F7308-DISCO

All these boards feature an SDRAM.

You need to check the features of each board in their respective UM to select the one that fits your needs (Dual core/Single Core, etc ..)

[ggowd.1]

Hi  SofLit,

Now we are planning to design our own PCB for STM32H745ZI Microcontroller for that can we integrate SDRAM (MT48LC4M32B2B5-6A IT_L TR) IC for that Board. 

Best Regards,
Gagan Gowda