/*=============================================================================Cyan Technology LimitedFILE - main.cDESCRIPTION    WAVE file playing and storage.    This software is designed to be used to allow external sound files    in raw sample format to be loaded into the eCOG via the UART and played    from an external memory. The output is generated using PWM and requires    external filtering and amplification.        We will attempt to put the whole SDRAM to use, using 0x8000 byte chunks    requiring 512 banks to be mapped independently        To Do:        Add option for stereo using PWM2    Tony Ward - March 2005=============================================================================*/#include <ecog.h>#include <ecog1.h>#include <stdio.h>#include <math.h>#include <string.h>#include "driver_lib.h"int uart_wav_read (void);int uart_input_check (char *);int flipend (int);unsigned int *rloc;                // Current record locationunsigned int *ploc;                // Current play locationint pbank, rbank;                  // Memory 'bank' numberint tv, a;                         // Temporary variablesint main(int argc, char* argv[]){    char input;    int sts = 0;    // Status flag        ssm_pwm1_clk(SSM_HIGH_PLL, 0);      // Maximum speed    fd.tim.ctrl_en.pwm1_auto_re_ld = 1; // Turn on automatic reload    rg.tim.pwm1_ld = 565;               // PWM load value    rg.tim.pwm1_val = 228;              // Default PWM change value = 50%        fd.emi.ctrl_sts.refr_en = 1;        // SDRAM hack to enable refresh    // Initialise the record and play pointers    rloc = (unsigned int *) 0x0000;    ploc = (unsigned int *) 0x0000;        duart_a_tx(':');    // Indicate working        while(1)    {        // Poll the UART and act on any received data        if (1 == fd.duart.a_sts.rx_1b_rdy)        {            input = rg.duart.a_rx & 0xff;            switch (input)            {                case ('l'):             // Load and play a wav file from UART                // sts will be 0 for complete, 1 for end memory or else 2                duart_a_tx('L');         // Display 'L'                sts = uart_wav_read();  // Run subroutine to read WAV file                duart_a_tx(sts + 48);   // Transmit the return status                break;                case ('s'): // stop                duart_a_tx('S');                fd.tim.int_dis1.pwm1_exp = 1;     // stop the pwm                fd.tim.ctrl_dis.pwm1_cnt = 1;                pbank = 0;        // Reset the playback bank                break;                case ('p'): // play                duart_a_tx('P');                // Map in the correct memory first                rg.mmu.ext_cs0_data0_phy = (pbank * 0x0080);                fd.tim.int_en1.pwm1_exp = 1;    // Enable interrupt                fd.tim.ctrl_en.pwm1_cnt = 1;    // Start the PWM                break;            }        }    }        return (0);}/*================================================================================  WAVE read functions================================================================================*/// Function for receiving wav file to memory via the UARTint uart_wav_read (void) {    unsigned long datasize;       // Size of incoming wav file    unsigned long icount;         // Input and output count variable        datasize = 500000;            // Explicit for now    icount = 0;    while (icount++ != datasize)        // Loop till end of memory/file        {            while (!fd.duart.a_sts.rx_2b_rdy | fd.duart.a_sts.rx_act)             ;                           // Wait for sample and frame        *rloc++ = (rg.duart.a_rx);      // use flipend here if needed        if (rloc == ((unsigned int *) 0x4000))    // End of bank reached        {            // Set location to beginning of bank            rloc = ((unsigned int *) 0x0000);                rbank++;                    // Increment current bank number            if (rbank == 0x0200)        // This is the end of memory, stop            {                rbank = 0;              // Reset bank number                return(1);            }            // We now need to remap the memory according to the bank number            rg.mmu.ext_cs0_data0_phy = (rbank * 0x0080);        }    }    return(0);}// Simple function to swap endianness of words if requiredint flipend (int in){    return(((in & 0x00ff) << 8) + ((in & 0xff00) >> 8));}/*================================================================================  Interrupt service routines (ISRs)================================================================================*/void __irq_entry pwm_handler (void){    unsigned int sample_val;        fd.tim.int_clr1.pwm1_exp = 1;       // Clear the interrupt    // We assume here that the sample is properly scaled to max PWM period length    sample_val = (*ploc++);             // Get sample from memory    rg.tim.pwm1_val = (sample_val);     // Output sample on PWM        // Now check and set the bank number if necessary    if (ploc == (unsigned int *) 0x4000)    // End of current bank reached    {        ploc = (unsigned int *) 0x0000;     // Set location to beginning of bank        pbank++;                            // Increment current bank number        if (pbank == 0x0200)                // This is the end of memory, stop        {            pbank = 0;                      // Reset bank number            fd.tim.int_dis1.pwm1_exp = 1;   // Turn off this interrupt        }        // We now need to remap the memory according to the bank number        rg.mmu.ext_cs0_data0_phy = (pbank * 0x0080);    }}