//=============================================================================
// File: PRU_mem1DTransfer.p 
// Desc: Simple 1-D memory transfer.
// Vers: 1.0
//
//  Copyright (c) 2009 Texas instruments,Incorporated
//  All rights reserved
//
//=============================================================================
//  Example to demonstrate simple 1-D data movement using PRU
//=============================================================================


// The MEM1D service routine facilitates simple 1D:1D transfer.
// Parameter Table: 
//
// 31________24________16________8________0  
// |                 SRC                  |
// |______________________________________|
// |                 DST                  |
// |______________________________________|
// |                 CNT                  |
// |______________________________________| 
//

.origin 0
.entrypoint MEM1D

#include "PRU_mem1DTransfer.hp"

MEM1D:
    // Load the MEM1D parameters in registers R7:R9
    LBCO      txParams, CONST_PRUDRAM, #0x00, SIZE(Mem1DParams)

    // If count is zero, return
    QBEQ      MEM1D_EXIT, txParams.cnt, #0x00

MEM1D_COPY:
    // Load burst length (in bytes)
    LDI       mem1d_eblen, #0x20

    // Load the data from source in registers R14-R21
    LBBO      mem1d_data, txParams.src, #0x00, b0 

    // Store the data to destination
    SBBO      mem1d_data, txParams.dst, #0x00, b0 

    // Calculate the remaining count
    SUB       txParams.cnt, txParams.cnt, mem1d_eblen

    // Update the source and destination registers
    ADD       txParams.src, txParams.src, mem1d_eblen
    ADD       txParams.dst, txParams.dst, mem1d_eblen
    
    // Store the current state back to PARAM
    SBCO      txParams.src, C3, #0x00, 12

    // If count is zero, transfer is complete, return
    QBEQ      MEM1D_EXIT, txParams.cnt, #0x00

    // Perform the burst again
    QBA       MEM1D_COPY

MEM1D_EXIT:  
    HALT