Hi,
I have been learning how to use CMSIS v5 Beta to program an LPC4357, and so far so good.
I got stuck in creating an interrupt for USART3 (Rx). I am using numerous other interrupts with no problem. I receive the following error when compiling:
Error: L6200E: Symbol USART3_IRQHandler multiply defined (by usart_lpc43xx.o and version1.o).
I am using the CMSIS Startup, system, DRIVER_USART, USART_LPC43xx files, and i receive the above error.
When debugging, and triggering an interrupt, it seems to go to the Hardfault handler??.
When examining the above files, there seems to be another "MX_USART3_IRQHandler", could someone explain this to me, or should i use this? How? I tried.
Could some one please help me out on this? Or/and provide me with a very basic program example for USARTn Interrupts using CMSIS v4.5.0 / v5.
I have realized that there are hardly any CMSIS examples around, especially UART. Though of course i might be wrong.
void USART3_IRQHandler() { volatile unsigned long iir; iir = LPC_USART3->IIR; //clear Interrupt NVIC_DisableIRQ(USART3_IRQn); NVIC_ClearPendingIRQ(USART3_IRQn); Driver_USART3.Send("\nCCCCCCCCCCCCCCCCCCC\n", 24); while (Driver_USART3.GetStatus().tx_busy); NVIC_EnableIRQ(USART3_IRQn); } void UART_Interrupt_Init() { LPC_USART3->IER = 0x03; NVIC_EnableIRQ(USART3_IRQn); }
UART3 without interrupts functions well. I did not place the UART3 Init code to simplify.
I am grateful for any help given.
So where do version1.o come from?
Another thing - best is if an ISR never performs any action that consumes more than a small fraction of the total interrupt frequency you will run the chip at. An UART that doesn't have a large enough transmit FIFO can't handle the transmission of multiple characters without locking up for multiple character transmit periods. But then you aren't ready to handle incomming data or timers etc.
So it's best to have a queue or similar for outgoing data and have the UART pick up more characters as they get sent.
Version1.c is my main .c file.
I found this also:
\fn void USART_IRQHandler (UART_RESOURCES *usart) \brief USART Interrupt handler. \param[in] usart Pointer to USART resources
Could anyone guide me on how to use it?
I hope someone can help.
Is this an issue with CMSIS v4.5.0 / v5?
In the CMSIS LPC43xx Startup file there is defined USART3_IRQHandler
and in the CMSIS USART_LPC43xx.c there is a defined USART3_IRQHandler
Due to this, the compiler is stating that there is a multiply Defined.
online it states the following:
The user application may simply define an interrupt handler function by using the handler name as shown below.
But the above is not possible in this case.
Can someone give me a solution? or a workaround?
Thank you
Could anyone with experience with using the UART on an LPC43xx and CMSIS help me out?
Can you guide me through this?