topic FLAT8000_P30 memory in S12 / MagniV Microcontrollers

FLAT8000_P30 memory

michaelsarafidi — Wed, 10 Oct 2012 06:46:00 GMT

hi there,

We are using HC12DG256 and Codewarrior 3.1. These days we are evaluating Codewarior 5.1.

We have opened our project with CW 5.1 built it and run it successfully.

What i want to ask is what is FLAT8000_P30 or flash window (memory from 0x8000 to 0xBFFF).

At CW3.1 this area was empty (0xFF), at CW5.1 is full.

Thanks in advance.

Re: FLAT8000_P30 memory

GordonD — Fri, 12 Oct 2012 14:25:48 GMT

Michael,

Where are you seeing the text "FLAT8000_P30" in the .map file? In the .prm file?

Regards,

Gordon

Re: FLAT8000_P30 memory

RadekS — Tue, 30 Oct 2012 13:54:41 GMT

At address 0x8000 to 0xBFFF is flash memory window.

S12DG256 is 16bit MCU, therefore we can directly address only 64kB memory range (0x0000~0xFFFF).

S12DG256 contain 256kB flash, this flash is divided to sixteen 16kB pages (page 30~3F). We can access whole flash trough memory window. At address 0x8000 to 0xBFFF is visible page content according PPAGE register settings. Two pages (3E, 3F) are accessible directly (0x4000~0x7FFF, 0xC000~0xFFFF) and we call them as non-banked.

Default placement for your code is paged flash (banked). Therefore you see your code at page 30.

For details, please check your project *.prm file. Placement of your code you can drive by #pragma commands (for example):

#pragma CODE_SEG NON_BANKED

//your code

#pragma CODE_SEG DEFAULT