/*--------------------------------------------------------------------------*/
/*
* MP3 player DEMO - MPEG queue management functions
* Copyright (C) 2006 MXP semicontuctor
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY and WUTHOUT ANY SUPPORT; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: lpc_io.c 1.0 2006/10/16 09:41:32 rob Exp $
*/
/*--------------------------------------------------------------------------*/
#include <targets/LPC2148.H>
#include <string.h>
#include "lpc_io.h"
#include "PLL_calc.h"
#define bool unsigned char
#define STREAM_DECODED_SIZE 1024
#define ENABLED 1
#define DISABLED 0
typedef struct {
short int raw[STREAM_DECODED_SIZE]; /* 16 bit PCM output samples [ch][sample] */
volatile unsigned short wr_idx;
volatile unsigned short rd_idx;
}decoded_stream_t;
unsigned short pippo;
static decoded_stream_t DecodedBuff;
static bool RenderStatus; /* Audio render status */
/* TRUE = render enabled , FALSE =render disabled */
#define DFIFO_DELETE() (DecodedBuff.wr_idx = DecodedBuff.rd_idx = 0)
#define IS_DFIFO_FULL() ((DecodedBuff.wr_idx+1)%STREAM_DECODED_SIZE == DecodedBuff.rd_idx)
#define IS_DFIFO_EMPTY() (DecodedBuff.wr_idx == DecodedBuff.rd_idx)
#define DFIFO_WRITE(S) do { \
DecodedBuff.raw[DecodedBuff.wr_idx] = S; \
DecodedBuff.wr_idx = ( (DecodedBuff.wr_idx+1)%STREAM_DECODED_SIZE ); \
}while(0)
#define DFIFO_READ(S) do { \
S = DecodedBuff.raw[DecodedBuff.rd_idx]; \
DecodedBuff.rd_idx = ( (DecodedBuff.rd_idx+1)%STREAM_DECODED_SIZE ); \
}while(0)
#define FIFO_LEN() ( DecodedBuff.wr_idx >= DecodedBuff.rd_idx ? \
DecodedBuff.wr_idx - DecodedBuff.rd_idx : \
DecodedBuff.wr_idx + (STREAM_DECODED_SIZE - DecodedBuff.rd_idx) )
void tc0 (void) __attribute__ ((interrupt)); // Manage timer Interrupt
void enable_audio_render(void)
{
if (RenderStatus == DISABLED)
{
T0TCR = 1; /* Timer0 Enable */
VICIntEnable = 0x00000010; /* Enable Timer0 Interrupt */
RenderStatus = ENABLED;
}
}
void disable_audio_render(void)
{
if (RenderStatus == ENABLED)
{
T0TCR = 0; /* Timer0 Disable */
VICIntEnable = 0x00000000; /* Disable Timer0 Interrupt */
RenderStatus = DISABLED;
}
}
void wait_end_of_excerpt(void)
{
while (!IS_DFIFO_EMPTY());
disable_audio_render();
}
inline void render_sample(short int sample)
{
while (IS_DFIFO_FULL());
DFIFO_WRITE(sample);
enable_audio_render();
}
void render_sample_block(short int *blk, unsigned short int len)
{
unsigned short i;
for (i=0; i<len; i++)
{
while (IS_DFIFO_FULL());
DFIFO_WRITE(*(blk+i));
}
enable_audio_render();
}
/* Setup the Timer Counter 0 Interrupt */
void init_timer ()
{
VICVectAddr0 = (unsigned long)tc0; // set interrupt vector in 0
VICVectCntl0 = 0x20 | 4; // use it for Timer 0 Interrupt
VICIntEnable = 0x00000010; // Enable Timer0 Interrupt
T0MCR = 3; // Interrupt and Reset on MR0
}
/* Timer Counter 0 Interrupt executes sample time @ 60 MHz CPU Clock */
void tc0 (void)
{
short int sample;
unsigned short dacr;
TOGGLE_LIVE_LED3();
if (!IS_DFIFO_EMPTY())
DFIFO_READ(sample);
else
{
TOGGLE_LIVE_LED2();
sample = 0;
}
dacr = (unsigned short)sample + (unsigned short)0x8000;
DACR = dacr & 0xFFC0; // send a mono 10 bit sample to the DAC
T0IR = 1; // Clear interrupt flag
VICVectAddr = 0; // Acknowledge Interrupt
}
void set_dac_sample_rate(unsigned int sample_rate)
{
unsigned int _T0MCR;
_T0MCR = ((unsigned int)cclk/sample_rate) - 1;
T0MR0 = _T0MCR;
}
void init_IO(void)
{
#ifdef DEBUG
IO1DIR = 0x00FF0000; /* P1.16..23 defined as Outputs */
#endif
DFIFO_DELETE();
RenderStatus = DISABLED;
init_timer();
__ARMLIB_enableIRQ(); /* Enable global interrupt */
}
