topic Re: How to share the const data between CPU12 and xgate? in S12 / MagniV Microcontrollers

How to share the const data between CPU12 and xgate?

100asong — Fri, 07 May 2010 15:14:00 GMT

Hi,Sir

Please give support about it,any advice is welcome.

I am transfering UCOS-II to MC9S12XEP,I let xgate create time tick.

The TickISR function in xgate is here:

void interrupt RtiHandler(int dataptr)
{

u8 y;

...

         ...
           y             = OSUnMapTbl[OSRdyGrp];          /* Get pointer to HPT ready to run              */
        OSPrioHighRdy = (INT8U)((y << 3) + OSUnMapTbl[OSRdyTbl[y]]);

      if(OSPrioHighRdy!=OSPrioCur)
      {
        asm("SIF");
        //{ SIF } ;
      }

}

OSUnMapTbl is defined in OS_CORE.c file.

INT8U const OSUnMapTbl[] = {
0, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x00 to 0x0F */

...

...
};

Now we can enter RTI_Handler,but y can not get the right value.

question:

1. whether we should add some sentence to share OSUnMapTbl?

I have a try here to share OSUnMapTbl:

#pragma CONST_SEG XGATE_CONST_FLASH

INT8U const OSUnMapTbl[] = {

...

#pragma CONST_SEG DEFAULT

But system can not enter RtiHandler interrupt.

question:

2.How to share const variable?

3.Why we can not enter RtiHandler since add " #pragma CONST_SEG XGATE_CONST_FLASH"

Please give me help.Wait online.thanks.

Re: How to share the const data between CPU12 and xgate?

kef — Fri, 07 May 2010 18:42:38 GMT

XGATE is able to access only 30k of flash on PPAGE's E0 and E1. Thus only constants in pages E0 and E1 can be shared. Also S12X should be told constants are far.

#pragma CONST_SEG XGATE_CONST

far INT8U const OSUnMapTbl[] = {
0, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, /* 0x00 to 0x0F */

...

...
};

#pragma CONST_SEG DEFAULT

Shared header file should include this:

#pragma CONST_SEG XGATE_CONST

extern far INT8U const OSUnMapTbl[];

#pragma CONST_SEG DEFAULT

Re: How to share the const data between CPU12 and xgate?

kef — Fri, 07 May 2010 20:42:21 GMT

1. "Expected ;" usually is a symptom of not recognised syntax. Maybe INTU8 is not defined in your code?

2. XGATE can't access misaligned words, thus XGATE compiler is padding >=2byte wide structure members. Try using in S12X code:

#pragma align on

#pragma align off

3. What you are doing is weird. You have two cores = you need to run two OS copies, one on S12X and another one on XGATE. From screenshot it looks like you are debugging the same OS on both cores. Shouldn't you try to run OS on one of cores first?

Re: How to share the const data between CPU12 and xgate?

100asong — Wed, 12 May 2010 11:44:40 GMT

I use xgate to sub 1 for TCBDly counter,and find the highest priority task.And CPU switch task.