CCS/TMS320F28377S: EXAMPLE CODE "usb_host_msc" is trap in "ILLEGAL_ISR" when run from FLASH

Tool/software: Code Composer Studio

Hi,

I am using TMS320F28377S processor and I want to run example code "usb_host_msc" from flash. I run this code from RAM and it is running properly. But when I select FLASH from activity configuration (image 1) and run code then program trap in to "ILLEGAL_ISR" (image2).

By step debug, I found program run up to  "ReadLine" function in "while(1)" and then it go in to "ILLEGAL_ISR". I am using CCS 8.2 and crystal frequency is 20Mhz.

I also try this on "C2000 Launch XL TMS320F28377S VER 1.0" but result are same. Only difference is that I use SCIC instead of SCIA.

I also change the system clock and aux clock using function "SysCtlClockSet" and "SysCtlAuxClockSet" function and try different combination but result are same.

/**********************************************************************************************************************************************************************/

SysCtlClockSet(SYSCTL_OSCSRC_XTAL | SYSCTL_PLL_ENABLE | SYSCTL_IMULT(20) | SYSCTL_SYSDIV(2));

SysCtlAuxClockSet(SYSCTL_OSCSRC_XTAL | SYSCTL_PLL_ENABLE | SYSCTL_IMULT(6) | SYSCTL_SYSDIV(2));

/***********************************************************************************************************************************************************************/

I also put DisableDog() function in start of main function but this has no effect. 

One more think I want to point out that I post this problem in forum and in replay every one say this example is working but almost always they run this code in dual core TMS320 processor. So please check this example given on location  "C:\ti\controlSUITE\device_support\F2837xS\v210\F2837xS_examples_Cpu1\usb_host_msc" on  TMS320F28377S.   

And I think this is not connection problem because as I mentioned that code is properly running form RAM  

I also attached  usb_host_msc.c file so please check this also.