isr.c

This experiment uses the Blackfi n BF533/BF537 EZ-KIT to run a simple FIR fi lter on stereo channe

///////////////////////////////////////////////////////////////////////////////
//
// 	
//  Experiment 6.11_BF533 Implement FIR filter using BF533 EZ-KIT
//  FILE name: ISR.c
//
//  Description: Perform real-time FIR filtering on stereo signals.
//		 Interrupt service routine to handle real-world signal.
//  
//  For the book "Embedded Signal Processing with the Micro Signal Architecture"
//		  By Woon-Seng Gan and Sen M. Kuo
//		  Publisher: John Wiley and Sons, Inc.
//
//  Tools used: VisualDSP++ v4.0 (running on BF533 EZ-KIT)
//
///////////////////////////////////////////////////////////////////////////////

#include "fir.h"


//--------------------------------------------------------------------------//
// Function:	Sport0_RX_ISR												//
//																			//
// Description: This ISR is executed after a complete frame of input data 	//
//				has been received. The new samples are stored in 			//
//				iCh0LeftIn and iCh0RightIn.  Then the function 				//
//				Process_Data() is called in which the fir filtering			//
//				routine can be executed.									//
//				After that the processed values are copied from the 		//
//				variables iCh0LeftOut and iCh0RightOut into the dma 		//
//				transmit buffer.											//
//--------------------------------------------------------------------------//
EX_INTERRUPT_HANDLER(Sport0_RX_ISR)
{
	int i;
	static short j=0,k=0;
	
	// confirm interrupt handling
	//BF533 Hardware Reference pg 9-32
	*pDMA1_IRQ_STATUS = 0x0001;
	
	// Move data from receive buffer to local buffer
	#pragma no_alias
	for (i = 0; i < IP_SIZE; i++)
	{
		// Retrieve all the samples from receive buffer to process buffer
		iCh0LeftIn[i] = iRxBuffer1[INTERNAL_ADC_L0+j];
		iCh0RightIn[i] = iRxBuffer1[INTERNAL_ADC_R0+j];
		
		// use the builtin circular buffer to update the index
		j = __builtin_circindex(j, 4, 4*IP_SIZE*FRAME_SIZE);
	}
	
	Process_Data();
	
	#pragma no_alias
	for (i=0; i<IP_SIZE; i++)
	{
		iTxBuffer1[INTERNAL_DAC_L0+k] = iCh0LeftOut[i];
		iTxBuffer1[INTERNAL_DAC_R0+k] = iCh0RightOut[i];
		
		// use the builtin circular buffer to update the index
		k = __builtin_circindex(k, 4, 4*IP_SIZE*FRAME_SIZE);
		
	}
}
	

//--------------------------------------------------------------------------//
// Function:	Timer_ISR													//
//																			//
// Description: Every time the ISR is invoked, the routine would read the	//
//				value of the switches SW[7:6]. This is to solve the problem	//
//				of any switch bouncing problem - switch deboucing solution!	//
//																			//
//--------------------------------------------------------------------------//

EX_INTERRUPT_HANDLER(Switch_ISR)
{
	if (*pFIO_FLAG_D & PF10)
	{
		pushbt_flag = 1;
		*pFIO_FLAG_C = PF10;
	}
	if (*pFIO_FLAG_D & PF11)
	{
		pushbt_flag = 0;
		*pFIO_FLAG_C = PF11;
	}
}