Squall Lin

MC13213 IRQ problem

Discussion created by Squall Lin on Mar 6, 2007
Latest reply on Feb 28, 2008 by Ruili Tian

We design a Evaluation Board referenced on MC13213-SRB schematic. We load the TestMode example application into our evaluation board and get a IRQ problem. when MCU HCS08 set to take the mc13213 modem out of rest and wait for modem interrupt , MCU can't detect the interrupt occur edge.

In this while loop , we fall into a infinite loop because of the check condition "if(IRQFLAG == 1)". We checked  the IRQSC register IRQF bit and fount it never changed

while (u8AttnIrq == FALSE)  {
  if (IRQFLAG == 1)  { //* Check to see if IRQ is asserted */
      u16IrqReg = SPIDrvRead(0x24); //*
      // * Clear MC13192 interrupts and
      // * check for ATTN IRQ from 13192
      // */
     u16IrqReg &= 0x400;
     if (u16IrqReg == 0)  {
         u8AttnIrq = FALSE;
     }
     else  {
         u8AttnIrq = TRUE;
     }
  }
}

We tried use the OSCILLOSCOPE to measure the Interrupt edge in MCU IRQ pin from test point, we found that , the interrupt edge in reference freescale 13213-SRB is droped from 3V to 2V , but the interrupt edge in our evaluation board is droped from 2V to 0V. We don't know if our PCB layout occur problem , can u help us checking if the PCB layout with any problem ?

bellow link1 is Document about mc13213 PCB layout guideline about MC13213 chip
ftp://fantasy.sinosys.com.tw/PCB1.JPG

bellow link2 is Out PCB layout about mc13213 chip
ftp://fantasy.sinosys.com.tw/PCB2.JPG

Does it will cause any undetermined problem ?

thx a lot

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