Kinetis L - Optimization stopps IF Loop functionality

edwardkäding — Wed, 02 Jul 2014 06:29:53 GMT

Hello Freescale Support Team,

As usual I apologise for my questions, if they have allready been answered in a different discussion.

I am working with the MKL02Z32VFM4 MCU, CodeWarrior v10.5 and not PE.

I am currently programming a Bootloader and therefore small size is of most importance.

Everything works fine, but after I run the Optimization "Optimize size (-Os)" nothing works anymore.

Using the debugger I figured out that the code is stuck at the first "if-Loop".

Here my code of my GetChar UART0 program, where the program is stuck:

----------------------------------------------------------------------------------------------------------------------------------------------------------------

void UART0_GetChar(unsigned char *value, unsigned char block) {

for (;;) {

if (ReceiveChar_Length > 0) { /* Is number of received chars greater than 0? */

NVIC_ICER |= NVIC_ICER_CLRENA(0x1000); /* Deactivate Rx-Interrupt. */

ReceiveChar_Length--; /* Decrease number of remaining received chars. */

NVIC_ICPR |= NVIC_ICPR_CLRPEND_MASK; /* Clear any Pending Interrupts. */

NVIC_ISER |= NVIC_ISER_SETENA(0x1000); /* Activate Rx-Interrupt. */

*value = InpBuffer[InpIndexR++]; /* Take value out of the buffer. */

if (InpIndexR >= RECEIVE_BUF_SIZE) { /* Is the index out of the receive buffer? */

InpIndexR = 0; /* Set index to the first item into the receive buffer. */

}

break;

}

else {

*value = -1;

if (!block) {

break;

}

----------------------------------------------------------------------------------------------------------------------------------------------------------------

block gets the value 1. The Interrupt still works fine, but then it just jumps back to if (!block) and stays there.

I believe that there will be even more problems after this issue is solved.

The Optimization would really help, because it reduces the size from about 5000 to 2900.

I thank everyone in advance for your great support,

Edward.

Re: Kinetis L - Optimization stopps IF Loop functionality

mjbcswitzerland — Wed, 02 Jul 2014 15:16:35 GMT

Hi Edward

Make sure that you have declared

volatile int ReceiveChar_Length = 0; [if not int, use whatever type it is - the volatile key word is the important bit]

If not, you may have this effect.

Regards

Mark

Re: Kinetis L - Optimization stopps IF Loop functionality

edwardkäding — Thu, 03 Jul 2014 06:13:23 GMT

Hello Mark,

Your advice solved my problem. I was quite surprised for this easy solution but after research I also read about this effect after Optimizations.

I thank you very much for your great and quick support.

I wish you and your team a great day,

Edward.

topic Kinetis L - Optimization stopps IF Loop functionality in Kinetis Microcontrollers

Kinetis L - Optimization stopps IF Loop functionality

Re: Kinetis L - Optimization stopps IF Loop functionality

Re: Kinetis L - Optimization stopps IF Loop functionality