topic Re: MCF5307 external SRAM size ? in ColdFire/68K Microcontrollers and Processors

MCF5307 external SRAM size ?

admin — Fri, 16 Jan 2009 18:41:16 GMT

Hi
I am new to MCF5307 and I have just taken over a project.
The MCF5307 has 16MB flash on CS0 and 4 MB SRAM on CS01.
Now the question is can I expand to 16MB SRAM on the CS01 or is there limit of the CS mask.
As i read it it should be possible to put 16MB of memory on each CS output or am I wrong.

Re: MCF5307 external SRAM size ?

JWW — Sun, 18 Jan 2009 03:15:54 GMT

It's been a long time since I've looked at that bus interface. But in our ColdFire bus units, as far as I can remember, we keep the base address register and the mask registers the same across chip selects. CS0 sometimes has special boot capability, but when it comes to mask and location they are the same.

Make sure to calculate your mask correctly and don't overlap your memory ranges.

Cheers

-JWW

Re: MCF5307 external SRAM size ?

admin — Mon, 19 Jan 2009 16:12:45 GMT

Hi

My memory map looks like this:

//-----------------------------------------------------------------------------------------------
#define FLASH_STANDARD_BASE             0x00000000L
#define FLASH_SIZE_HUGE_X               0x01000000L             /* 16MB

#define SRAM_STANDARD_BASE              0x55000000L
#define SRAM_SIZE_HUGE                  0x00400000L             /* 4MB

#define FRAM_STANDARD_BASE              0xAA000000L     /*4KB

#define CS_2_7_BASE                     0xFF000000L             /*
//-----------------------------------------------------------------------------------------------

I would like to change the 4MB SRAM to16 MB.
and I would define "SRAM_SIZE_MORE_HUGE                  0x01000000L     /* 16MB */"
Can you se anything wrong in this ?

Christian..