Hyper RAM

How many mixed of HyperRAM / HyperFlash can exist on the same bus? What are the limitations and critical points?

e.g.

2x HyperRAM  + 1 x HyperFlash

1x HyperRAM  + 2 x HyperFlash

Thx.

I working on some hardware that will use the S70K HyperRAM.

The hardware guide for HyperRAM, where it talks about layout requirements and such, makes a vague reference to using terminations if required. I don't have access to signal integrity tools so I have no way of knowing if the termination resistors will be required or not. My board will be pretty small (less than 1" x 2"), so I will place the RAM as close to the MCU as physically possible.

One of the demo kits for a microcontroller I am considering (STM32H7 variant) places series resistors at the HyperRAM pins only. As the data pins are bidirectional, I'm not sure why the terminations would only be needed in one direction (in this case RAM->MCU but not MCU->RAM).

Does anyone have any advice?

My application will use a NXP imxRT1050 FlexSPI summunication with two memory devices:

  Cypress S27KS0641DPBHV020

  Cypress S26KS256SDPBHV020

Cypress Document AN211622, section 4.1 recommends that the connecting transmission lines have 50 ohms characteristic impedance. 

The question:  Why 50 ohms characteristic impedance?  Neither the memory device drivers and receivers nor, insofar as I know, the FlexSPI port drivers and receivers, have 50 homs characteristic impedance.

HyperRAM has two device technologies.

   - 63nm DRAM Process Technology

   - 38nm DRAM Process Technology

Are there any functional differences between them?

I understand that the speed is different.

I am wondering if the commands and usage are different.

I was hoping to do some preliminary development with HyperRAM and a Xilinx FPGA, but am having some trouble finding anything pre-built.  I found one option, the S7 mini, but the distributor says that they won't have any more units until February 2021.  I wrote Cypress, who linked me up to someone at Avnet (who also deals with Xilinx), and they were unaware of any other boards.  So as a last ditch effort to make sure I turned over every rock, I figured I would check here before I give up. Thanks.

Hi

Is the Verilog model of S70KS1282 same as S27KS0642 ?

Thanks.

BR

Grace

Hello,

Can you guide me, please? I am going to use these 5 memories (include HyperRAm and HyperFlash) by HyperBus interface:

1. 64 Mb HyperRAM Self-Refresh DRAM (S27KL0642/S27KS0642)

2. 128 Mb HyperRAM Self-Refresh DRAM (S70KL1282/S70KS1282)

3. 512 Mb HyperFlashTM (S26KL512S/S26KS512S)

4. 256 Mb HyperFlashTM (S26KL512S/S26KS512S)

5. 128 Mb HyperFlashTM (S26KL512S/S26KS512S)

Are all these 5 memories pin-to-pin compatible, so they can be used with the same ZIF socket?

Thank you and regards,

Golnaz