i.MXRT 1170 with 16bit HyperRAM replace to 32bit SDRAM

[FreshV5]

Dear Sir:             

I read the MIMXRT1170 EVK Board Hardware User’s Guide from NXP official website.

The key components of i.RT1170 EVK as below:

• SOC: MIMXRT1176DVMAA
• DRAM: W9825G6KH-5I 2ea, 16Mb*16 SDRAM,200MHz, total 32bit data bus.
• FLASH: 128Mb Qual SPI flash. (133MHz SDR mode)

Because original SDRAM is a high pin-count and hardly to purchase too, I want to use HyperRAM to replace SDRAM.

I refer to the officially platform and want to make 2ea 16bit SDRAM (16bit * 200MHz * 2ea = 800MB/s), so I need to use 2ea HyperRAM to replace it to meet same data bus? (8bit * 2ea * 2 (DDR) * 200MHz = 800MB/s). At present, I got two solutions to do that.

1. FlexSPI-1 and FlexSPI-2 connect one HyperRAM each and it can build a 16bit data bus, but 4bit-SPI flash will be connected to the low-speed interface. 
2. FlexSPI-1 use Qspi FLASH as normal and use FlexSPI-2 to connect 2ea 8bit HyperRAM chipsets. how can make up data bus up to 16 bit or more than 16bit (like 32bit or 64 bit)?Flexspi2.A_DATA[0:7] + Flexspi2.B_DATA[0:7] connect to two DQ[0:7] of HyperRAM?
3. How about other controllor pin to connect?

 Could you advise a solution how to use HyperRAM to replace SDRAM and it can yield best preference?

[victorjimenez · Accepted solution]

Hello, 

FlexSPI-1 and FlexSPI-2 connect one HyperRAM each and it can build a 16bit data bus, but 4bit-SPI flash will be connected to the low-speed interface.

I don't find this implementation very useful since the performance that you will have while doing XiP will be very poor.

FlexSPI-1 use Qspi FLASH as normal and use FlexSPI-2 to connect 2ea 8bit HyperRAM chipsets. how can make up data bus up to 16 bit or more than 16bit (like 32bit or 64 bit)?Flexspi2.A_DATA[0:7] + Flexspi2.B_DATA[0:7] connect to two DQ[0:7] of HyperRAM?

This implementation seems to be the way to go. You can take advantage of the 2 FlexSPI interfaces that the RT1170 has. This way, you can connect the QSPI memory to one FlexSPI and the HyperRAM to the other one. It's not possible to connect 32-bit or 64-bit memories through the FlexSPI interface. In section 30.3.1 of the reference manual, you will find the connections that you can make in a FlexSPI interface.

How about other controllor pin to connect?

As mentioned in the last question, the best approach will be that you connect the QSPI memory to one interface and the HyperRAM to the other. I recommend you to check the following application note. Although this document is for the RT150, the same principles apply to the RT1170, but there's one difference. Since the RT1050 only has one FlexSPI interface, if you want to use the HyperRAM instead of the Hyperflash, you need to remove the Hyperflash. This is not the case for the RT1170 since you have two interfaces.

Regards,
Victor 

[FreshV5]

Victor:

Thanks for your help.

I found the document<IMX-RT1170-CROSSOVER-MCUS-FLEXSPI-CONTROLLER by Martin Lapis>. It is like a detailed statement for section 30.3.1 of RT1170 Reference Manual.

So, it can be accessed to 16bit data bus if two HyperRAM connect with FlexSPI2. Or up to 4ea HyperRAM chips connect with FlexSPI2 to make more capacity but only access to 16bit data bus maximum.

QuadSPI flash or OctalSPI flash connects with FlexSPI1 as normal and we can get the best preformation.