TMS320F28388D: USB interrupt can not be nested.

Strong ZHANG

Part Number: TMS320F28388D
Other Parts Discussed in Thread: C2000WARE

Hi Expert,

My customer want to use USB interrupt nested by XINT which is INT1.4, they do the configuration below, but the code will go to Interrupt_defaultHandler,

if they do not add the nest code below, then everything is ok.

There are two question about USB function:

1. Can USB0DeviceIntHandler function be nested?

2. customer think USB0DeviceIntHandler take up too much time which is about 14us, is it possible to optimize the code to reduce the time?

it is not open source code to customer and they say they are not able to modify the code by themselves.

over 2 years ago

0 Omer Amir over 2 years ago

TI__Mastermind 30185 points

Hello,

An expert will get back to you by tomorrow.

Best regards,

Omer Amir

0 Lori Heustess over 2 years ago

TI__Guru* 92140 points

Strong,

I will let the USB expert comment on question 2.

For question 1 -

The USB ISR is in PIE group 9, but the code shown is modifying the PIEIER for group 1 (PIEIER1). This is causing the issue. The PIEIERx should only be modified within a groupx ISR. From this reference: https://software-dl.ti.com/C2000/docs/c28x_interrupt_nesting/html/index.html

If the goal is only to re-enable group 1 ISRs, then the group level priority (PIEIER9) does not need to be modified. Only the global priority (IER at the CPU level) needs to re-enable interrupt 1 and then clear the interrupt mask INTM.

Best regards

Lori

0 Siddharth Deshpande over 2 years ago in reply to Lori Heustess

TI__Mastermind 35955 points

Hi,

For the second question, the USB Library source code is available in C2000Ware located at <c2000ware>\libraries\communications\usb\f2838x\.

The USB0DeviceIntHandler() function is implemented in usbdhandler.c file .

Best Regards

Siddharth

C2000™︎ microcontrollers

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TMS320F28388D: USB interrupt can not be nested.