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BSP setting for USB

Question asked by Teckna Teckna on Jan 11, 2012
Latest reply on Jun 2, 2012 by EARL GOODRICH

Hi everyone,

 

I'm working on a custom board with CW10, MQX 3.8 and K60N512 processor.

 

With this board I have successfully worked with MQX 3.7. Now that I ported all custom drivers to MQX 3.8, everything is ok except the USB. I cloned the BSP twrk60n512 and I modified the line 58 in the bsp_cm.h file from

#define CPU_XTAL_CLK_HZ                 0x02FAF080U /* Value of the external crystal or oscillator clock frequency in Hz */

to

#define CPU_XTAL_CLK_HZ                 0x016E3600U /* Value of the external crystal or oscillator clock frequency in Hz */

(my external clock is 24 MHz instead of 50 MHz as in the twrk60n512 board)

 

When I insert the USB cable in the PC port the device is not recognized, even if leave the 50 MHz define.

The only way I found to make the USB work is to set the SIM_CLKDIV2.USBDIV field to 0 instead of 1 in the Cpu_SetClockConfiguration function: I modified the line 717 in the bsp_cm.c file from

      SIM_CLKDIV2 = (uint32_t)((SIM_CLKDIV2 & (uint32_t)~0x0DUL) | (uint32_t)0x02UL); /* Update USB clock prescalers */

to

      SIM_CLKDIV2 = (uint32_t)(SIM_CLKDIV2 & (uint32_t)~0x0FUL); /* Update USB clock prescalers */

Am I right or do I have to modifiy other things?

Any other advice?

 

Many thanks

Teckna

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