AVR Freaks

Hello and thank you for your response.

It seems when “_sercom_usart_interrupt_handler” within hpl_sercom.h is attempting to set:

device->usart_cb.tx_byte_sent(device);

it fails within the critical section of

static inline void hri_sercomusart_write_DATA_reg(const void *const hw, hri_sercomusart_data_reg_t data)

{

            SERCOM_CRITICAL_SECTION_ENTER();

            ((Sercom *)hw)->USART.DATA.reg = data;

            SERCOM_CRITICAL_SECTION_LEAVE();

}

I done two captures

• one successful run with IRQ disabled
• one unsuccessful run with IRQ enabled

Working(IRQ Disabled)

Non-Working (IRQ enabled)

I tried to capture the exception type but to no avail as the debugger just hangs after attempting to set above register = data.

I see that the dummy handler has the following error (if I have collected correctly)

As required " A generic clock (GCLK_EIC) is required to clock the peripheral. This clock must be configured and enabled in the Generic Clock Controller before using the peripheral. This generic clock is asynchronous to the user interface clock (CLK_EIC_APB). Due to this asynchronicity, writes to certain registers will require synchronization between the clock domains." - https://microchipdeveloper.com/3...

I configured where they are all on generic glock 0 derived from 8Mhz Internal Oscillator

Many thanks for your time