lpc_io.rar_ARM7 LPC_lpc ARM7

/*--------------------------------------------------------------------------*/ /* * 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 */ }