MK64FN, Flexbus and external memory

[wfwf]

Hello,

I've been searching for a while but not finding an comprehensive answer. Any hint or link to an existent post will even be much appreciated.

I'm trying to connect a MK64FN1M0Vxx12 to an external NAND memory, in particular a Spansion S34ML04G1. I know this MCU hasn't a NFC controller, that's why I'd like to connect it with the flexbus to then use the processor expert for an "easy" configuration. Is it possible? I have a further SDcard module to connect to the K64, I have only 8bit data bus for both of them and maybe the only Chip select pin is enough to communicate to both of them. Is it true?

The available pins on the NAND are : CLE, ALE, CE, WE, RE, WP, R/B

As found on the link below, the only connections I'm "sure" of are FB_ALE(->ALE), FB_CS0b (->CE), and FB_RWb(->WE). Which K64 pin one must connect the others to?

Where to connect the data pin?

External SRAM and non-multiplexed Flexbus

Re: Configure the FlexBus peripheral

K20 FlexBus component in Processor expert? 

thank you!

[wfwf]

Hi Ping and Hao,

thank you very much, it's way clearer now. Do you have an English version of the first document?

Why do you say that the 4GB NAND module would't be usable via software simulated method? Is there a fixed upper limit, and what does it depend on?

Do you think that using just the available GPIOs will it be a simpler solution? Is there a reliable library one can adapt to this case?

thank you again

W

[cutworth]

Hi WF,

No, currently I do not have an English version for this document. I can share when I have it. I don't think we can support 4GB NAND with software simulated method, ECC calculation with CPU core has lots of workload for big sized NAND. It mostly depends on how many ECC bits you need to support.

Implementing with GPIO method surely will have slower performance than with Flexbus plus glue logic method. If you can tolerant slow access to NAND, you can of course use this method.

For the soft nand support, you can refer to the following code based on MQX. Extract this into mqx\source\io folder.

Hao

[cutworth]

Hi WF,

You cannot connect NAND Flash directly with Flexbus. You will need some glue logic. Attached schematic and hardware user guide for a reference design which uses K60 flexbus to connect external NAND flash. Please note, as there is no ECC support in Flexbus, you will need to use soft ECC in code and due to big workload on MCU for ECC calculation. Connecting NAND with software simulated method does not allow you to connect big NAND flash. The NAND flash we used on board is 64MB.

Hao

[jeremyzhou]

Hi

It's possible to connect the NAND Flash directly by using the Flexbus interface, however it's not very usual and simple.

The problem is the NAND flash is block oriented and need some software error corrections.So it means that system needs software driver which takes care about this.

But we don't have such standalone driver for this now.

Hope it helps.
Have a great day,
Ping

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