ColdFire/68K Microcontrollers and ProcessorsのトピックRe: M52235 and External Memory

M52235 and External Memory

admin — Thu, 04 May 2006 07:34:55 GMT

Is the M52235 capable of accessing external memory? MMC and SD cards interface through SPI (as far as I know), and is there any way of using the M52235's QSPI to connect, and access one of those, or any external memory IC's?

Thanks, Benjamin Roy

Re: M52235 and External Memory

DavidS — Thu, 04 May 2006 09:39:20 GMT

Hi BenjaminRoy,

The MCF5223x family of ColdFire microcontrollers does not support external memory for flash, sram and/or dram.

If memory is accessible via SPI or I2C then we have then ability to do so but we do have to start the boot process from internal flash first.

Hope this helps.

Regards, DavidS

Re: M52235 and External Memory

admin — Thu, 04 May 2006 21:30:12 GMT

Say I wanted to host a large page on the M52235. It would be well over the size of the coldfire's memory. Could the M52235 boot off it's internal flash/sram and then load the page off the SD Card?

Is there any schematics or special hardware needed for the QSPI interface to the memory card? The memory cards' pinouts that I think are SPI are here:

http://pinouts.ru/data/memorysrick_pinout.shtml
http://pinouts.ru/data/sdcard_pinout.shtml
http://pinouts.ru/data/mmcard_pinout.shtml

By there way, is there a way that a hard drive could be interfaced to the M52235?

Re: M52235 and External Memory

DavidS — Sat, 06 May 2006 02:21:19 GMT

Hi BenjaminRoy,

SST and Spansion have external flash memories that have a SPI interface.

You could bit bang a protocol on GPIO for the memory sticks you've sent links to but that bandwidth would be far less than using the intergrates SPI bus.

I do not have an example SPI to Flash schematic.

Regards, DavidS