Kinetis MicrocontrollersのトピックK66 SDRAM always addressing same location

K66 SDRAM always addressing same location

jch4416 — Thu, 26 Oct 2017 15:41:36 GMT

Hello,

I'm using a MK66FX1M0VMD18 with a 16bit AS4C4M16SA-TIN SDRAM. The SDRAM has 8 column addresses, so the connections between it and the K66 are the same as in Table 35-7 of the K66 Family Reference Manual, with A21-22 on the K66 going to BA0-1 on the SDRAM.

The problem we are having is that if I write a value to a specific address, then I will get that same value back for every address that I then read. So it is essentially as if the SDRAM controller ignores the address in the CPU instruction and always accesses the same SDRAM location.

Has anyone seen this isssue before?

Thanks,

Jim

Re: K66 SDRAM always addressing same location

Hui_Ma — Tue, 31 Oct 2017 03:08:18 GMT

Hi Jim,

The K66 chip provides the cache for SDRAM memory with below setting:

Please check if the cache was enabled at your application.

If yes, you could try to close the cache and check the issue again.

Have a great day,
Ma Hui

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