Diff: USBDEV/USBAudio/usbdmain.c

Revision:

0:bf7b9fba3924

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBDEV/USBAudio/usbdmain.c	Sun Mar 20 05:38:56 2011 +0000
@@ -0,0 +1,178 @@
+/*----------------------------------------------------------------------------
+ * Name:    usbmain.c
+ * Purpose: USB Audio Class Demo
+ * Version: V1.20
+ *----------------------------------------------------------------------------
+ *      This software is supplied "AS IS" without any warranties, express,
+ *      implied or statutory, including but not limited to the implied
+ *      warranties of fitness for purpose, satisfactory quality and
+ *      noninfringement. Keil extends you a royalty-free right to reproduce
+ *      and distribute executable files created using this software for use
+ *      on NXP Semiconductors LPC microcontroller devices only. Nothing else
+ *      gives you the right to use this software.
+ *
+ * Copyright (c) 2009 Keil - An ARM Company. All rights reserved.
+ *---------------------------------------------------------------------------*/
+
+#include "LPC17xx.h"                        /* LPC17xx definitions */
+#include "lpc_types.h"
+
+#include "usb.h"
+#include "usbcfg.h"
+#include "usbhw.h"
+#include "usbcore.h"
+#include "usbaudio.h"
+
+/* Example group ----------------------------------------------------------- */
+/** @defgroup USBDEV_USBAudio	USBAudio
+ * @ingroup USBDEV_Examples
+ * @{
+ */
+uint8_t  Mute;                                 /* Mute State */
+uint32_t Volume;                               /* Volume Level */
+
+#if USB_DMA
+uint32_t *InfoBuf = (uint32_t *)(DMA_BUF_ADR);
+short *DataBuf = (short *)(DMA_BUF_ADR + 4*P_C);
+#else
+uint32_t InfoBuf[P_C];
+short DataBuf[B_S];                         /* Data Buffer */
+#endif
+
+uint16_t  DataOut;                              /* Data Out Index */
+uint16_t  DataIn;                               /* Data In Index */
+
+uint8_t   DataRun;                              /* Data Stream Run State */
+uint16_t  PotVal;                               /* Potenciometer Value */
+uint32_t  VUM;                                  /* VU Meter */
+uint32_t  Tick;                                 /* Time Tick */
+
+
+/*
+ * Get Potenciometer Value
+ */
+
+void get_potval (void) {
+  uint32_t val;
+
+  LPC_ADC->ADCR |= 0x01000000;              /* Start A/D Conversion */
+  do {
+    val = LPC_ADC->ADGDR;                   /* Read A/D Data Register */
+  } while ((val & 0x80000000) == 0);        /* Wait for end of A/D Conversion */
+  LPC_ADC->ADCR &= ~0x01000000;             /* Stop A/D Conversion */
+  PotVal = ((val >> 8) & 0xF8) +            /* Extract Potenciometer Value */
+           ((val >> 7) & 0x08);
+}
+
+
+/*
+ * Timer Counter 0 Interrupt Service Routine
+ *   executed each 31.25us (32kHz frequency)
+ */
+
+void TIMER0_IRQHandler(void)
+{
+  long  val;
+  uint32_t cnt;
+
+  if (DataRun) {                            /* Data Stream is running */
+    val = DataBuf[DataOut];                 /* Get Audio Sample */
+    cnt = (DataIn - DataOut) & (B_S - 1);   /* Buffer Data Count */
+    if (cnt == (B_S - P_C*P_S)) {           /* Too much Data in Buffer */
+      DataOut++;                            /* Skip one Sample */
+    }
+    if (cnt > (P_C*P_S)) {                  /* Still enough Data in Buffer */
+      DataOut++;                            /* Update Data Out Index */
+    }
+    DataOut &= B_S - 1;                     /* Adjust Buffer Out Index */
+    if (val < 0) VUM -= val;                /* Accumulate Neg Value */
+    else         VUM += val;                /* Accumulate Pos Value */
+    val  *= Volume;                         /* Apply Volume Level */
+    val >>= 16;                             /* Adjust Value */
+    val  += 0x8000;                         /* Add Bias */
+    val  &= 0xFFFF;                         /* Mask Value */
+  } else {
+    val = 0x8000;                           /* DAC Middle Point */
+  }
+
+  if (Mute) {
+    val = 0x8000;                           /* DAC Middle Point */
+  }
+
+  LPC_DAC->DACR = val & 0xFFC0;             /* Set Speaker Output */
+
+  if ((Tick++ & 0x03FF) == 0) {             /* On every 1024th Tick */
+    get_potval();                           /* Get Potenciometer Value */
+    if (VolCur == 0x8000) {                 /* Check for Minimum Level */
+      Volume = 0;                           /* No Sound */
+    } else {
+      Volume = VolCur * PotVal;             /* Chained Volume Level */
+    }
+    val = VUM >> 20;                        /* Scale Accumulated Value */
+    VUM = 0;                                /* Clear VUM */
+    if (val > 7) val = 7;                   /* Limit Value */
+  }
+
+  LPC_TIM0->IR = 1;                         /* Clear Interrupt Flag */
+}
+
+
+
+/*****************************************************************************
+**   Main Function  main()
+******************************************************************************/
+int main (void)
+{
+  volatile uint32_t pclkdiv, pclk;
+
+//  SystemInit();
+
+  LPC_PINCON->PINSEL1 &=~((0x03<<18)|(0x03<<20));
+  /* P0.25, A0.0, function 01, P0.26 AOUT, function 10 */
+  LPC_PINCON->PINSEL1 |= ((0x01<<18)|(0x02<<20));
+
+  /* Enable CLOCK into ADC controller */
+  LPC_SC->PCONP |= (1 << 12);
+
+  LPC_ADC->ADCR = 0x00200E04;		/* ADC: 10-bit AIN2 @ 4MHz */
+  LPC_DAC->DACR = 0x00008000;		/* DAC Output set to Middle Point */
+
+  /* By default, the PCLKSELx value is zero, thus, the PCLK for
+  all the peripherals is 1/4 of the SystemFrequency. */
+  /* Bit 2~3 is for TIMER0 */
+  pclkdiv = (LPC_SC->PCLKSEL0 >> 2) & 0x03;
+  switch ( pclkdiv )
+  {
+	case 0x00:
+	default:
+	  pclk = SystemCoreClock/4;
+	break;
+	case 0x01:
+	  pclk = SystemCoreClock;
+	break;
+	case 0x02:
+	  pclk = SystemCoreClock/2;
+	break;
+	case 0x03:
+	  pclk = SystemCoreClock/8;
+	break;
+  }
+
+  LPC_TIM0->MR0 = pclk/DATA_FREQ - 1;	/* TC0 Match Value 0 */
+  LPC_TIM0->MCR = 3;					/* TCO Interrupt and Reset on MR0 */
+  LPC_TIM0->TCR = 1;					/* TC0 Enable */
+  NVIC_EnableIRQ(TIMER0_IRQn);
+
+  USB_Init();				/* USB Initialization */
+  USB_Connect(TRUE);		/* USB Connect */
+
+  /********* The main Function is an endless loop ***********/
+  while( 1 );
+}
+
+/******************************************************************************
+**                            End Of File
+******************************************************************************/
+/*
+ * @}
+ */