dma_burst.asm

开发环境为visual dsp++3.0的DSP高速端口测试程序

//---------------------------------------------------------------------------------------------------------
// 
// (C) Copyright 2002 - Analog Devices, Inc.  All rights reserved.
//
// File Name:		DMA_Burst.asm
// 
// Date Modified:	4/11/02		Rev 1.0
// 
// Purpose:			DMA burst mode example					
//
//---------------------------------------------------------------------------------------------------------
#include <def21160.h>

#define N 16		// number of 32-bit words to transfer

.GLOBAL		_main;

.section/dm seg_sbsram;

.var External_Buffer[N]; 

.endseg;

.section/dm seg_dmda;

.var Internal_TX_Buffer[N] =0x00000000, 0x11111111, 0x22222222, 0x33333333, 
							0x44444444, 0x55555555, 0x66666666, 0x77777777, 
							0x88888888, 0x99999999, 0xaaaaaaaa, 0xbbbbbbbb, 
							0xcccccccc, 0xdddddddd, 0xeeeeeeee, 0xffffffff;
.var Internal_RX_Buffer[N];

.endseg;


.section/pm seg_pmco;
start:
_main:

		// enable external port 0 DMA and global interupts
		bit set imask EP0I;			
		bit set MODE1 IRPTEN;		

		// set MSIZE 1100
		ustat1 = dm(SYSCON);		
		bit set ustat1 0x0000C000; 	
		dm(SYSCON) = ustat1;		

		// set the External Port 0 waitstates to 1 
		ustat1 = dm(WAIT);				
		bit set ustat1 0x00000080; 		
		bit clr ustat1 0x00000300; 	
		dm(WAIT) = ustat1;		


	// Fill destination buffer with 0s 	
	Clear_External_Buffer:
		b0 = 0;					// clear b0 register
		i0 = External_Buffer;	// point to the destination buffer
		l0 = 0;					// no circular buffering				
		m0 = 1;					// set modify to 1
		
		r0 = 0x00; 										// value to set dest to
		r1 = @External_Buffer;							// set number of locations to clear
		lcntr = r1, do Clear_Ext_Memory until lce;
				dm(i0,m0) = r0;							// clear the memory
			Clear_Ext_Memory:
				nop;

	Clear_Internal_RX_Buffer:
		b0 = 0;						// clear b0 register
		i0 = Internal_RX_Buffer;	// point to the destination buffer
		l0 = 0;						// no circular buffering
		m0 = 1;						// set modify to 1
		
		r0 = 0x00; 				// value to set dest to
		r1 = @Internal_RX_Buffer;	// Set number of locations to clear
		lcntr = r1, do Clear_Int_Memory until lce;
				dm(i0,m0) = r0;		// clear the memory
			Clear_Int_Memory:
				nop;




	// Write 16 words of data from the Internal_TX_Buffer to the External SBSRAM
	// The DSP does not support burst write transfers becuase the single-cycle write 
 	// capability of SBSRAMs achieves the same throughput level, with less complexity.  
	Setup_Send_Internal_Data_DMA:
		r0=0;		
		dm(DMAC10)=r0;  // Clear DMA Control Register
	
	    r0=Internal_TX_Buffer; 	
		dm(II10)=r0; 	// load IIx register with int. mem. source
	
		r0=1;     	
		dm(IM10)=r0; 	// load internal modify value  
	  
	    r0=@Internal_TX_Buffer;	
		dm(C10)=r0;  	// load internal count value
	
	    r0=External_Buffer;   	
		dm(EI10)=r0; 	// load EIx register with destination in ext. mem.
	
	    r0=1;      	
		dm(EM10)=r0; 	// load external modify value
	
	    r0=@Internal_TX_Buffer;	
		dm(EC10)=r0; 	// load external count
	
		r0=0x00000405; 	
		dm(DMAC10)=r0;  // dma enable, int>ext, master mode		                
		
		idle;

	// Read back 16 words of data from the external SBSRAM in burst mode
	Setup_Receive_External_Data_DMA:
		r0=0;		
		dm(DMAC10)=r0;  // Clear DMA Control Register
	
	    r0=Internal_RX_Buffer; 	
		dm(II10)=r0; 	// load IIx register with int. mem. source
	
		r0=1;     	
		dm(IM10)=r0; 	// load internal modify value  
	  
	    r0=@Internal_RX_Buffer;	
		dm(C10)=r0;  	// load internal count value
	
	    r0=External_Buffer;   	
		dm(EI10)=r0; 	// load EIx register with ext. mem. destination
	
	    r0=1;      	
		dm(EM10)=r0; 	// load external modify value
	
	    r0=@Internal_RX_Buffer;	
		dm(EC10)=r0; 	// load external count
	
	    r0=0x00080401; 	
		dm(DMAC10)=r0;  // enable burst, dma enable, ext->int, master mode		                

		idle;
    
		r0=0;		
		dm(DMAC10)=r0;  // Clear DMA Control Register


	// Compare Internal_TX_Buffer with Internal_RX_Buffer
	Verify_DMA:
		b0 = 0;						// clear b0 register
		i0 = Internal_TX_Buffer;	// point to the origin buffer
		l0 = 0;						// no circular buffering
		m0 = 1;						// set modify to 1

		b1 = 0;						// clear b0 register
		i1 = Internal_RX_Buffer;	// point to the origin buffer
		l1 = 0;						// no circular buffering
		m1 = 1;						// set modify to 1
		
		r1 = @Internal_RX_Buffer;					// set number of locations to read
		lcntr = r1, do Verify_Mem until lce;
				r0 = dm(i0,m0);						// Get TX value
				r1 = dm(i1,m1);						// get RX value
				COMP(r0,r1);						// check to see if equal
				if ne jump DMA_Fail;
			Verify_Mem:
				nop;

	DMA_Pass:  nop;
		jump DMA_Pass;
	
	DMA_Fail:  nop;
		jump DMA_Fail;


_main.end:

.endseg;