LE4 CW 6.2 Understanding RAM allocation

UtopiaTim — Thu, 25 Dec 2008 03:37:03 GMT

Hi Folks,

Been having a bit of problems with RAM allocation on the LE4.

Here's my question (probably not understanding)!

Code is determining which values to take from a look-up table in FLASH:

void LCD_pos_buf(unsigned char pos, unsigned char display){

LCDWF14 = WF14_mirror;                          // always have icon on

if (pos == 1){
     temp = numbers[(display*2)];
     LCDWF9 = temp;
     temp = numbers[(display*2)+1];
     LCDWF10 = temp;
     WF10_mirror = temp;
}

Here's the .MAP info from object list sorted by address:

     __OVL_11_LCD_pos_buf_14__PSID_7530005c.72         52       2       2       3   .overlap
     __OVL_11_LCD_pos_buf_14__PSID_7530005b.71         54       2       2       3   .overlap
     __OVL_11_LCD_pos_buf_14__PSID_75300059.70         56       2       2       3   .overlap
     __OVL_11_LCD_pos_buf_14__PSID_75300057.69         58       2       2       3   .overlap
     __OVL_11_LCD_pos_buf_14__PSID_75300056.68         5A       2       2       3   .overlap
     __OVL_11_LCD_pos_buf_14__PSID_75300054.67         5C       2       2       5   .overlap

The code takes 12 bytes of RAM.

If I put another chunk of code following the 1st with if (pos == 2)...., then

it takes another 12 bytes of RAM.

Why doesn't the compiler reuse the RAM? At this rate, I run out of RAM pretty

quickly.

Thanks!

Tim

Re: LE4 CW 6.2 Understanding RAM allocation

CompilerGuru — Thu, 25 Dec 2008 08:30:04 GMT

Does the compiler option "-Ostk: Reuse Locals of Stack Frame" change this?

Daniel

Re: LE4 CW 6.2 Understanding RAM allocation

UtopiaTim — Thu, 25 Dec 2008 12:31:50 GMT

Hi Daniel,

Thank you so much for the info. That fixed the allocation problem.

Now I have a lot of RAM left over!

As far as the compiler using the RAM1 block, I have started a

service request, and I got a reply that the RAM1 block is not

used correctly. Since the LE4 is a new part, I guess not

everything got checked.

But, you have fixed my problem!

Thanks for the Christmas present & hope you have a good

holiday season & a prosperous 2009!!

Tim

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LE4 CW 6.2 Understanding RAM allocation

Re: LE4 CW 6.2 Understanding RAM allocation

Re: LE4 CW 6.2 Understanding RAM allocation