Hi, all
I'm trying to solve stream-broken in usart through MF.
Through usart bus, 21760 bytes as speed of 250kbps should be transferred. When I tested with netduino based PK with large buffer(I modified RxQueue to receive all data), sometimes data is missing. Every time the index of missing is changing, so I think it is not related with logic in C# app.
Below is a part of netduino source related with USART.
void STM32_USART_Handle_RX_IRQ (int ComPortNum, USART_TypeDef* uart)
{
INTERRUPT_START;
char c = (char)(uart->DR); // read RX data
USART_AddCharToRxBuffer(ComPortNum, c);
Events_Set(SYSTEM_EVENT_FLAG_COM_IN);
INTERRUPT_END;
}
I thought it is related with AddCharToRxBuffer, so I used this test code in Keil with debugger.
(the length of data is fixed, so I used MAX_STRLEN for checking stream is finished)
void STM32_USART_Handle_RX_IRQ (int ComPortNum, USART_TypeDef* uart)
{
INTERRUPT_START;
if(cnt < MAX_STRLEN)
{
char c = (char)(uart->DR); // read RX data
received_string[cnt] = (char)(uart->DR);
cnt++;
}
else
{
for(int i = 0; i < MAX_STRLEN; i++)
{
USART_AddCharToRxBuffer(ComPortNum, received_string[i]);
Events_Set(SYSTEM_EVENT_FLAG_COM_IN);
}
cnt = 0;
}
INTERRUPT_END;
}
When I confirm the data in received_string array while PC is hang in else condition, the data is different with original one.
Now I am suppose it is timing issue.
- Usart Interrupt Clock or
- Thread/Timer issue related with other core function or
I'm not expert in native and embedded, so I'm checking every module one by one. I wonder which part can be related with this issue.
P.S. I tested also native example, and it works. So this is not hardware problem.
Jiwon
