add sound card

ch55xduino/ch55x/libraries/Generic_Examples/examples/05.USB/SoundCard/SoundCard.ino

@@ -0,0 +1,41 @@
+/*
+  USB sound card example
+
+  created 2024
+  by Deqing Sun for use with CH55xduino
+
+  CH552 act as mono 24000K sound card
+  playback high 8bit on P3.4
+
+  Improved from ziv2013's work
+
+  This example code is in the public domain.
+
+  cli board options: usb_settings=user148
+
+*/
+
+#ifndef USER_USB_RAM
+#error "This example needs to be compiled with a USER USB setting"
+#endif
+
+#include "src/USBAudioSpeaker/USBAudioSpeaker.h"
+
+void setup() {
+
+  USBInit();
+
+  // PWM2 is on P3.4
+  pinMode(34, OUTPUT);
+  // turn on PWM2
+  PIN_FUNC &= ~(bPWM2_PIN_X);
+  // Set PWM to Fsys/256 with 1 divider
+  PWM_CK_SE = 1;
+  PWM_CTRL |= bPWM2_OUT_EN;
+  PWM_DATA2 = 128;
+}
+
+
+void loop() {
+
+}

ch55xduino/ch55x/libraries/Generic_Examples/examples/05.USB/SoundCard/src/USBAudioSpeaker/USBAudioSpeaker.c

@@ -0,0 +1,155 @@
+// clang-format off
+#include <Arduino.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include "include/ch5xx.h"
+#include "include/ch5xx_usb.h"
+#include "USBconstant.h"
+#include "USBhandler.h"
+#include "USBAudioSpeaker.h"
+// clang-format on
+
+__xdata volatile uint8_t soundBufferPlayBackIndex = 0;
+
+#define T2_RELOAD_VALUE (65536 - F_CPU / 24000)
+#define T2_RELOAD_VALUE_LOW (T2_RELOAD_VALUE & 0xFF)
+#define T2_RELOAD_VALUE_HIGH ((T2_RELOAD_VALUE >> 8) & 0xFF)
+#define T2_RELOAD_VALUE_NEAR_FINISH (65536 - F_CPU / 24000 / 4)
+#define T2_RELOAD_VALUE_NEAR_FINISH_LOW (T2_RELOAD_VALUE_NEAR_FINISH & 0xFF)
+#define T2_RELOAD_VALUE_NEAR_FINISH_HIGH                                       \
+  ((T2_RELOAD_VALUE_NEAR_FINISH >> 8) & 0xFF)
+
+void Timer2Interrupt(void) __interrupt {
+  //   if (TF2) {
+  //     TF2 = 0;
+  //     __data signed char highByteOfPCM =
+  //     Ep1Buffer[(soundBufferPlayBackIndex<<1)+1];
+  //     __data unsigned char highByteOfPCMUnsigned = highByteOfPCM+128;
+
+  //     PWM_CTRL |= bPWM_IF_END;
+  //     while (!(PWM_CTRL & bPWM_IF_END));
+  //     PWM_DATA2 = highByteOfPCMUnsigned;
+  //     soundBufferPlayBackIndex++;
+  //   }
+
+  // due to PWM bug, https://github.com/DeqingSun/ch55xduino/issues/135
+  // we need to carefully handle the PWM data
+  // and SDCC is not good at handling partial inline assembly.
+  // we just do everything in inline assembly.
+  __asm__(";check if TF2 is set                    \n"
+          "    jb   _TF2,notSkipTimer2INTR$        \n"
+          "    sjmp skipTimer2INTR$                \n"
+          "notSkipTimer2INTR$:                     \n"
+          "    clr  _TF2                           \n"
+
+          ";get (soundBufferPlayBackIndex<<1)+1    \n"
+          ";also inc soundBufferPlayBackIndex      \n"
+          "    mov dptr,#_soundBufferPlayBackIndex \n"
+          "    movx a,@dptr                        \n"
+          "    mov r7,a                            \n"
+          ";check if soundBufferPlayBackIndex is too big \n"
+          "    add a,#232                          \n"
+          "    jnc soundBufferPlayBackIndexNotBig$ \n"
+          "    sjmp skipTimer2INTR$                \n"
+          "soundBufferPlayBackIndexNotBig$:        \n"
+          "    mov a,r7                            \n"
+          "    inc a                               \n"
+          "    movx @dptr,a                        \n"
+          "    mov a,r7                            \n"
+          "    rl	a                                \n"
+          "    inc a                               \n"
+
+          ";get Ep1Buffer[(soundBufferPlayBackIndex<<1)+1] \n"
+          "    add a,#_Ep1Buffer                   \n"
+          "    mov dpl,a                           \n"
+          "    clr a                               \n"
+          "    addc a,#(_Ep1Buffer >> 8)           \n"
+          "    mov dph,a                           \n"
+          "    movx a,@dptr                        \n"
+
+          ";add 128 for PWM                        \n"
+          "    mov r7,a                            \n"
+          "    mov a,#0x80                         \n"
+          "    add a,r7                            \n"
+          "    mov r7,a                            \n"
+
+          ";load previous PWM                      \n"
+          "    mov a,_PWM_DATA2                    \n"
+          "    add a,#232                          \n"
+          "    jnc previousPWMSmall$               \n"
+          ";if previous PWM was 20~25              \n"
+          ";we have chance to update PWM on the falling edge \n"
+          ";and that triggers bug of PWM           \n"
+          ";so we just wait after falling in that case \n"
+
+          ";previousPWM not Small, just set at beginning \n"
+          ";clear bPWM_IF_END                      \n"
+          "    orl _PWM_CTRL,#0x10                 \n"
+          ";wait for bPWM_IF_END                   \n"
+          "waitPWM_IF_END$:                        \n"
+          "    mov a,_PWM_CTRL                     \n"
+          "    jnb acc.4,waitPWM_IF_END$           \n"
+          "    mov a,r7                            \n"
+          "    mov  _PWM_DATA2,a                   \n"
+          "    sjmp pwmSetFinish$                  \n"
+
+          "previousPWMSmall$:                      \n"
+          ";clear bPWM_IF_END                      \n"
+          "    orl _PWM_CTRL,#0x10                 \n"
+          ";wait for bPWM_IF_END                   \n"
+          "waitPWM_IF_END_small$:                  \n"
+          "    mov a,_PWM_CTRL                     \n"
+          "    jnb acc.4,waitPWM_IF_END_small$     \n"
+          "    mov a,r7                            \n"
+          "    nop\n nop\n nop\n nop\n nop\n         "
+          "    nop\n nop\n nop\n nop\n nop\n         "
+          "    nop\n nop\n nop\n nop\n nop\n         "
+          "    nop\n nop\n nop\n nop\n nop\n         "
+          "    nop\n nop\n nop\n nop\n nop\n         "
+
+          "    mov  _PWM_DATA2,a                   \n"
+
+          "pwmSetFinish$:                          \n"
+
+          "skipTimer2INTR$:                        \n");
+}
+
+void USBInit() {
+  USBDeviceCfg();         // Device mode configuration
+  USBDeviceEndPointCfg(); // Endpoint configuration
+  USBDeviceIntCfg();      // Interrupt configuration
+  UEP0_T_LEN = 0;
+  UEP1_T_LEN = 0; // Pre-use send length must be cleared
+
+  for (uint8_t i = 0; i < 48; i++) {
+    Ep1Buffer[i] = 0;
+  }
+
+  T2CON = 0x00;
+  // bTMR_CLK may be set by uart0, we keep it as is.
+  T2MOD |= bTMR_CLK | bT2_CLK; // use Fsys for T2
+
+  TL2 = 0;
+  TH2 = 0;
+  RCAP2L = T2_RELOAD_VALUE_LOW;
+  RCAP2H = T2_RELOAD_VALUE_HIGH;
+
+  ET2 = 1;
+  TR2 = 1;
+}
+
+void AUDIO_EP1_Out(void) {
+
+  // Force T2 interrupt to sync with the data received
+  TR2 = 0;
+  TF2 = 0;
+  // the last data will be played back during the new data is being received
+  // just make sure the last data is played back before the new last data is
+  // received
+  TL2 = T2_RELOAD_VALUE_NEAR_FINISH_LOW;
+  TH2 = T2_RELOAD_VALUE_NEAR_FINISH_HIGH;
+  soundBufferPlayBackIndex = 0;
+  TR2 = 1;
+
+  UEP1_CTRL = UEP1_CTRL & ~MASK_UEP_T_RES | UEP_T_RES_TOUT;
+}

ch55xduino/ch55x/libraries/Generic_Examples/examples/05.USB/SoundCard/src/USBAudioSpeaker/USBAudioSpeaker.h

@@ -0,0 +1,23 @@
+#ifndef __USB_AUDIO_SPEAKER_H__
+#define __USB_AUDIO_SPEAKER_H__
+
+// clang-format off
+#include <stdint.h>
+#include "include/ch5xx.h"
+#include "include/ch5xx_usb.h"
+#include "USBhandler.h"
+// clang-format on
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void USBInit(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+void AUDIO_EP1_Out(void);
+
+#endif