CQ Publishing
Transistor Gijutsu, October 2014, Special Features Chapter 9， Software of the Function Generator トランジスタ技術2014年10月号 特集第9章のソフトウェア わがまま波形発生器のソフトウェア
Information
tg_201410s8_AD7714 トランジスタ技術 2014年 10月号 第9章のソフトウェア
Program for Section 9 in October. 2014 issue of the Transistor Gijutsu
(Japanese electronics magazine)
概要
このプログラムは、ソフトウエアDDSにより、任意の波形を出力（2ch）します。 特徴は次のとおりです。
- PWM出力をDAコンバータとして利用します。
- 周波数や波形、バースト条件などを個別に設定できる独立した出力を２チャネル持っています。
- 周波数分解能0.023ｍHz
- 周波数範囲0.023ｍHz～１０ｋHz
- 各チャネルにそれぞれ、波形の先頭で出力されるトリガ出力があります。
- 出力波形を関数で定義できます。
- 休止波数、出力波数、を設定することでバースト波形が出力できます。
ファイル
このソフトウエアは、次のファイルから構成されています。
- DDS.cpp - DDSによる波形発生
- main.cpp - main()関数
詳細については、10月号の記事および上記ファイル中のコメントを参照してください。
Diff: USBDevice/USBAudio/USBAudio.cpp
- Revision:
- 0:f1ecca559ec3
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/USBDevice/USBAudio/USBAudio.cpp Fri Aug 29 08:33:17 2014 +0000
@@ -0,0 +1,618 @@
+/* Copyright (c) 2010-2011 mbed.org, MIT License
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+* and associated documentation files (the "Software"), to deal in the Software without
+* restriction, including without limitation the rights to use, copy, modify, merge, publish,
+* distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in all copies or
+* substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include "stdint.h"
+#include "USBAudio.h"
+#include "USBAudio_Types.h"
+
+
+
+USBAudio::USBAudio(uint32_t frequency_in, uint8_t channel_nb_in, uint32_t frequency_out, uint8_t channel_nb_out, uint16_t vendor_id, uint16_t product_id, uint16_t product_release): USBDevice(vendor_id, product_id, product_release) {
+ mute = 0;
+ volCur = 0x0080;
+ volMin = 0x0000;
+ volMax = 0x0100;
+ volRes = 0x0004;
+ available = false;
+
+ FREQ_IN = frequency_in;
+ FREQ_OUT = frequency_out;
+
+ this->channel_nb_in = channel_nb_in;
+ this->channel_nb_out = channel_nb_out;
+
+ // stereo -> *2, mono -> *1
+ PACKET_SIZE_ISO_IN = (FREQ_IN / 500) * channel_nb_in;
+ PACKET_SIZE_ISO_OUT = (FREQ_OUT / 500) * channel_nb_out;
+
+ // STEREO -> left and right
+ channel_config_in = (channel_nb_in == 1) ? CHANNEL_M : CHANNEL_L + CHANNEL_R;
+ channel_config_out = (channel_nb_out == 1) ? CHANNEL_M : CHANNEL_L + CHANNEL_R;
+
+ SOF_handler = false;
+
+ buf_stream_out = NULL;
+ buf_stream_in = NULL;
+
+ interruptOUT = false;
+ writeIN = false;
+ interruptIN = false;
+ available = false;
+
+ volume = 0;
+
+ // connect the device
+ USBDevice::connect();
+}
+
+bool USBAudio::read(uint8_t * buf) {
+ buf_stream_in = buf;
+ SOF_handler = false;
+ while (!available || !SOF_handler);
+ available = false;
+ return true;
+}
+
+bool USBAudio::readNB(uint8_t * buf) {
+ buf_stream_in = buf;
+ SOF_handler = false;
+ while (!SOF_handler);
+ if (available) {
+ available = false;
+ buf_stream_in = NULL;
+ return true;
+ }
+ return false;
+}
+
+bool USBAudio::readWrite(uint8_t * buf_read, uint8_t * buf_write) {
+ buf_stream_in = buf_read;
+ SOF_handler = false;
+ writeIN = false;
+ if (interruptIN) {
+ USBDevice::writeNB(EP3IN, buf_write, PACKET_SIZE_ISO_OUT, PACKET_SIZE_ISO_OUT);
+ } else {
+ buf_stream_out = buf_write;
+ }
+ while (!available);
+ if (interruptIN) {
+ while (!writeIN);
+ }
+ while (!SOF_handler);
+ return true;
+}
+
+
+bool USBAudio::write(uint8_t * buf) {
+ writeIN = false;
+ SOF_handler = false;
+ if (interruptIN) {
+ USBDevice::writeNB(EP3IN, buf, PACKET_SIZE_ISO_OUT, PACKET_SIZE_ISO_OUT);
+ } else {
+ buf_stream_out = buf;
+ }
+ while (!SOF_handler);
+ if (interruptIN) {
+ while (!writeIN);
+ }
+ return true;
+}
+
+
+float USBAudio::getVolume() {
+ return (mute) ? 0.0 : volume;
+}
+
+
+bool USBAudio::EP3_OUT_callback() {
+ uint32_t size = 0;
+ interruptOUT = true;
+ if (buf_stream_in != NULL) {
+ readEP(EP3OUT, (uint8_t *)buf_stream_in, &size, PACKET_SIZE_ISO_IN);
+ available = true;
+ buf_stream_in = NULL;
+ }
+ readStart(EP3OUT, PACKET_SIZE_ISO_IN);
+ return false;
+}
+
+
+bool USBAudio::EP3_IN_callback() {
+ interruptIN = true;
+ writeIN = true;
+ return true;
+}
+
+
+
+// Called in ISR context on each start of frame
+void USBAudio::SOF(int frameNumber) {
+ uint32_t size = 0;
+
+ if (!interruptOUT) {
+ // read the isochronous endpoint
+ if (buf_stream_in != NULL) {
+ if (USBDevice::readEP_NB(EP3OUT, (uint8_t *)buf_stream_in, &size, PACKET_SIZE_ISO_IN)) {
+ if (size) {
+ available = true;
+ readStart(EP3OUT, PACKET_SIZE_ISO_IN);
+ buf_stream_in = NULL;
+ }
+ }
+ }
+ }
+
+ if (!interruptIN) {
+ // write if needed
+ if (buf_stream_out != NULL) {
+ USBDevice::writeNB(EP3IN, (uint8_t *)buf_stream_out, PACKET_SIZE_ISO_OUT, PACKET_SIZE_ISO_OUT);
+ buf_stream_out = NULL;
+ }
+ }
+
+ SOF_handler = true;
+}
+
+
+// Called in ISR context
+// Set configuration. Return false if the configuration is not supported.
+bool USBAudio::USBCallback_setConfiguration(uint8_t configuration) {
+ if (configuration != DEFAULT_CONFIGURATION) {
+ return false;
+ }
+
+ // Configure isochronous endpoint
+ realiseEndpoint(EP3OUT, PACKET_SIZE_ISO_IN, ISOCHRONOUS);
+ realiseEndpoint(EP3IN, PACKET_SIZE_ISO_OUT, ISOCHRONOUS);
+
+ // activate readings on this endpoint
+ readStart(EP3OUT, PACKET_SIZE_ISO_IN);
+ return true;
+}
+
+
+// Called in ISR context
+// Set alternate setting. Return false if the alternate setting is not supported
+bool USBAudio::USBCallback_setInterface(uint16_t interface, uint8_t alternate) {
+ if (interface == 0 && alternate == 0) {
+ return true;
+ }
+ if (interface == 1 && (alternate == 0 || alternate == 1)) {
+ return true;
+ }
+ if (interface == 2 && (alternate == 0 || alternate == 1)) {
+ return true;
+ }
+ return false;
+}
+
+
+
+// Called in ISR context
+// Called by USBDevice on Endpoint0 request
+// This is used to handle extensions to standard requests and class specific requests.
+// Return true if class handles this request
+bool USBAudio::USBCallback_request() {
+ bool success = false;
+ CONTROL_TRANSFER * transfer = getTransferPtr();
+
+ // Process class-specific requests
+ if (transfer->setup.bmRequestType.Type == CLASS_TYPE) {
+
+ // Feature Unit: Interface = 0, ID = 2
+ if (transfer->setup.wIndex == 0x0200) {
+
+ // Master Channel
+ if ((transfer->setup.wValue & 0xff) == 0) {
+
+ switch (transfer->setup.wValue >> 8) {
+ case MUTE_CONTROL:
+ switch (transfer->setup.bRequest) {
+ case REQUEST_GET_CUR:
+ transfer->remaining = 1;
+ transfer->ptr = &mute;
+ transfer->direction = DEVICE_TO_HOST;
+ success = true;
+ break;
+
+ case REQUEST_SET_CUR:
+ transfer->remaining = 1;
+ transfer->notify = true;
+ transfer->direction = HOST_TO_DEVICE;
+ success = true;
+ break;
+ default:
+ break;
+ }
+ break;
+ case VOLUME_CONTROL:
+ switch (transfer->setup.bRequest) {
+ case REQUEST_GET_CUR:
+ transfer->remaining = 2;
+ transfer->ptr = (uint8_t *)&volCur;
+ transfer->direction = DEVICE_TO_HOST;
+ success = true;
+ break;
+ case REQUEST_GET_MIN:
+ transfer->remaining = 2;
+ transfer->ptr = (uint8_t *)&volMin;
+ transfer->direction = DEVICE_TO_HOST;
+ success = true;
+ break;
+ case REQUEST_GET_MAX:
+ transfer->remaining = 2;
+ transfer->ptr = (uint8_t *)&volMax;
+ transfer->direction = DEVICE_TO_HOST;
+ success = true;
+ break;
+ case REQUEST_GET_RES:
+ transfer->remaining = 2;
+ transfer->ptr = (uint8_t *)&volRes;
+ transfer->direction = DEVICE_TO_HOST;
+ success = true;
+ break;
+
+ case REQUEST_SET_CUR:
+ transfer->remaining = 2;
+ transfer->notify = true;
+ transfer->direction = HOST_TO_DEVICE;
+ success = true;
+ break;
+ case REQUEST_SET_MIN:
+ transfer->remaining = 2;
+ transfer->notify = true;
+ transfer->direction = HOST_TO_DEVICE;
+ success = true;
+ break;
+ case REQUEST_SET_MAX:
+ transfer->remaining = 2;
+ transfer->notify = true;
+ transfer->direction = HOST_TO_DEVICE;
+ success = true;
+ break;
+ case REQUEST_SET_RES:
+ transfer->remaining = 2;
+ transfer->notify = true;
+ transfer->direction = HOST_TO_DEVICE;
+ success = true;
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ }
+ }
+ return success;
+}
+
+
+// Called in ISR context when a data OUT stage has been performed
+void USBAudio::USBCallback_requestCompleted(uint8_t * buf, uint32_t length) {
+ if ((length == 1) || (length == 2)) {
+ uint16_t data = (length == 1) ? *buf : *((uint16_t *)buf);
+ CONTROL_TRANSFER * transfer = getTransferPtr();
+ switch (transfer->setup.wValue >> 8) {
+ case MUTE_CONTROL:
+ switch (transfer->setup.bRequest) {
+ case REQUEST_SET_CUR:
+ mute = data & 0xff;
+ updateVol.call();
+ break;
+ default:
+ break;
+ }
+ break;
+ case VOLUME_CONTROL:
+ switch (transfer->setup.bRequest) {
+ case REQUEST_SET_CUR:
+ volCur = data;
+ volume = (float)volCur/(float)volMax;
+ updateVol.call();
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+
+
+#define TOTAL_DESCRIPTOR_LENGTH ((1 * CONFIGURATION_DESCRIPTOR_LENGTH) \
+ + (5 * INTERFACE_DESCRIPTOR_LENGTH) \
+ + (1 * CONTROL_INTERFACE_DESCRIPTOR_LENGTH + 1) \
+ + (2 * INPUT_TERMINAL_DESCRIPTOR_LENGTH) \
+ + (1 * FEATURE_UNIT_DESCRIPTOR_LENGTH) \
+ + (2 * OUTPUT_TERMINAL_DESCRIPTOR_LENGTH) \
+ + (2 * STREAMING_INTERFACE_DESCRIPTOR_LENGTH) \
+ + (2 * FORMAT_TYPE_I_DESCRIPTOR_LENGTH) \
+ + (2 * (ENDPOINT_DESCRIPTOR_LENGTH + 2)) \
+ + (2 * STREAMING_ENDPOINT_DESCRIPTOR_LENGTH) )
+
+#define TOTAL_CONTROL_INTF_LENGTH (CONTROL_INTERFACE_DESCRIPTOR_LENGTH + 1 + \
+ 2*INPUT_TERMINAL_DESCRIPTOR_LENGTH + \
+ FEATURE_UNIT_DESCRIPTOR_LENGTH + \
+ 2*OUTPUT_TERMINAL_DESCRIPTOR_LENGTH)
+
+uint8_t * USBAudio::configurationDesc() {
+ static uint8_t configDescriptor[] = {
+ // Configuration 1
+ CONFIGURATION_DESCRIPTOR_LENGTH, // bLength
+ CONFIGURATION_DESCRIPTOR, // bDescriptorType
+ LSB(TOTAL_DESCRIPTOR_LENGTH), // wTotalLength (LSB)
+ MSB(TOTAL_DESCRIPTOR_LENGTH), // wTotalLength (MSB)
+ 0x03, // bNumInterfaces
+ DEFAULT_CONFIGURATION, // bConfigurationValue
+ 0x00, // iConfiguration
+ 0x80, // bmAttributes
+ 50, // bMaxPower
+
+ // Interface 0, Alternate Setting 0, Audio Control
+ INTERFACE_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR, // bDescriptorType
+ 0x00, // bInterfaceNumber
+ 0x00, // bAlternateSetting
+ 0x00, // bNumEndpoints
+ AUDIO_CLASS, // bInterfaceClass
+ SUBCLASS_AUDIOCONTROL, // bInterfaceSubClass
+ 0x00, // bInterfaceProtocol
+ 0x00, // iInterface
+
+
+ // Audio Control Interface
+ CONTROL_INTERFACE_DESCRIPTOR_LENGTH + 1,// bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ CONTROL_HEADER, // bDescriptorSubtype
+ LSB(0x0100), // bcdADC (LSB)
+ MSB(0x0100), // bcdADC (MSB)
+ LSB(TOTAL_CONTROL_INTF_LENGTH), // wTotalLength
+ MSB(TOTAL_CONTROL_INTF_LENGTH), // wTotalLength
+ 0x02, // bInCollection
+ 0x01, // baInterfaceNr
+ 0x02, // baInterfaceNr
+
+ // Audio Input Terminal (Speaker)
+ INPUT_TERMINAL_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ CONTROL_INPUT_TERMINAL, // bDescriptorSubtype
+ 0x01, // bTerminalID
+ LSB(TERMINAL_USB_STREAMING), // wTerminalType
+ MSB(TERMINAL_USB_STREAMING), // wTerminalType
+ 0x00, // bAssocTerminal
+ channel_nb_in, // bNrChannels
+ (uint8_t)(LSB(channel_config_in)), // wChannelConfig
+ (uint8_t)(MSB(channel_config_in)), // wChannelConfig
+ 0x00, // iChannelNames
+ 0x00, // iTerminal
+
+ // Audio Feature Unit (Speaker)
+ FEATURE_UNIT_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ CONTROL_FEATURE_UNIT, // bDescriptorSubtype
+ 0x02, // bUnitID
+ 0x01, // bSourceID
+ 0x01, // bControlSize
+ CONTROL_MUTE |
+ CONTROL_VOLUME, // bmaControls(0)
+ 0x00, // bmaControls(1)
+ 0x00, // iTerminal
+
+ // Audio Output Terminal (Speaker)
+ OUTPUT_TERMINAL_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ CONTROL_OUTPUT_TERMINAL, // bDescriptorSubtype
+ 0x03, // bTerminalID
+ LSB(TERMINAL_SPEAKER), // wTerminalType
+ MSB(TERMINAL_SPEAKER), // wTerminalType
+ 0x00, // bAssocTerminal
+ 0x02, // bSourceID
+ 0x00, // iTerminal
+
+
+ // Audio Input Terminal (Microphone)
+ INPUT_TERMINAL_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ CONTROL_INPUT_TERMINAL, // bDescriptorSubtype
+ 0x04, // bTerminalID
+ LSB(TERMINAL_MICROPHONE), // wTerminalType
+ MSB(TERMINAL_MICROPHONE), // wTerminalType
+ 0x00, // bAssocTerminal
+ channel_nb_out, // bNrChannels
+ (uint8_t)(LSB(channel_config_out)), // wChannelConfig
+ (uint8_t)(MSB(channel_config_out)), // wChannelConfig
+ 0x00, // iChannelNames
+ 0x00, // iTerminal
+
+ // Audio Output Terminal (Microphone)
+ OUTPUT_TERMINAL_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ CONTROL_OUTPUT_TERMINAL, // bDescriptorSubtype
+ 0x05, // bTerminalID
+ LSB(TERMINAL_USB_STREAMING), // wTerminalType
+ MSB(TERMINAL_USB_STREAMING), // wTerminalType
+ 0x00, // bAssocTerminal
+ 0x04, // bSourceID
+ 0x00, // iTerminal
+
+
+
+
+
+
+ // Interface 1, Alternate Setting 0, Audio Streaming - Zero Bandwith
+ INTERFACE_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR, // bDescriptorType
+ 0x01, // bInterfaceNumber
+ 0x00, // bAlternateSetting
+ 0x00, // bNumEndpoints
+ AUDIO_CLASS, // bInterfaceClass
+ SUBCLASS_AUDIOSTREAMING, // bInterfaceSubClass
+ 0x00, // bInterfaceProtocol
+ 0x00, // iInterface
+
+ // Interface 1, Alternate Setting 1, Audio Streaming - Operational
+ INTERFACE_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR, // bDescriptorType
+ 0x01, // bInterfaceNumber
+ 0x01, // bAlternateSetting
+ 0x01, // bNumEndpoints
+ AUDIO_CLASS, // bInterfaceClass
+ SUBCLASS_AUDIOSTREAMING, // bInterfaceSubClass
+ 0x00, // bInterfaceProtocol
+ 0x00, // iInterface
+
+ // Audio Streaming Interface
+ STREAMING_INTERFACE_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ STREAMING_GENERAL, // bDescriptorSubtype
+ 0x01, // bTerminalLink
+ 0x00, // bDelay
+ LSB(FORMAT_PCM), // wFormatTag
+ MSB(FORMAT_PCM), // wFormatTag
+
+ // Audio Type I Format
+ FORMAT_TYPE_I_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ STREAMING_FORMAT_TYPE, // bDescriptorSubtype
+ FORMAT_TYPE_I, // bFormatType
+ channel_nb_in, // bNrChannels
+ 0x02, // bSubFrameSize
+ 16, // bBitResolution
+ 0x01, // bSamFreqType
+ (uint8_t)(LSB(FREQ_IN)), // tSamFreq
+ (uint8_t)((FREQ_IN >> 8) & 0xff), // tSamFreq
+ (uint8_t)((FREQ_IN >> 16) & 0xff), // tSamFreq
+
+ // Endpoint - Standard Descriptor
+ ENDPOINT_DESCRIPTOR_LENGTH + 2, // bLength
+ ENDPOINT_DESCRIPTOR, // bDescriptorType
+ PHY_TO_DESC(EPISO_OUT), // bEndpointAddress
+ E_ISOCHRONOUS, // bmAttributes
+ (uint8_t)(LSB(PACKET_SIZE_ISO_IN)), // wMaxPacketSize
+ (uint8_t)(MSB(PACKET_SIZE_ISO_IN)), // wMaxPacketSize
+ 0x01, // bInterval
+ 0x00, // bRefresh
+ 0x00, // bSynchAddress
+
+ // Endpoint - Audio Streaming
+ STREAMING_ENDPOINT_DESCRIPTOR_LENGTH, // bLength
+ ENDPOINT_DESCRIPTOR_TYPE, // bDescriptorType
+ ENDPOINT_GENERAL, // bDescriptor
+ 0x00, // bmAttributes
+ 0x00, // bLockDelayUnits
+ LSB(0x0000), // wLockDelay
+ MSB(0x0000), // wLockDelay
+
+
+
+
+
+
+
+ // Interface 1, Alternate Setting 0, Audio Streaming - Zero Bandwith
+ INTERFACE_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR, // bDescriptorType
+ 0x02, // bInterfaceNumber
+ 0x00, // bAlternateSetting
+ 0x00, // bNumEndpoints
+ AUDIO_CLASS, // bInterfaceClass
+ SUBCLASS_AUDIOSTREAMING, // bInterfaceSubClass
+ 0x00, // bInterfaceProtocol
+ 0x00, // iInterface
+
+ // Interface 1, Alternate Setting 1, Audio Streaming - Operational
+ INTERFACE_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR, // bDescriptorType
+ 0x02, // bInterfaceNumber
+ 0x01, // bAlternateSetting
+ 0x01, // bNumEndpoints
+ AUDIO_CLASS, // bInterfaceClass
+ SUBCLASS_AUDIOSTREAMING, // bInterfaceSubClass
+ 0x00, // bInterfaceProtocol
+ 0x00, // iInterface
+
+ // Audio Streaming Interface
+ STREAMING_INTERFACE_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ SUBCLASS_AUDIOCONTROL, // bDescriptorSubtype
+ 0x05, // bTerminalLink (output terminal microphone)
+ 0x01, // bDelay
+ 0x01, // wFormatTag
+ 0x00, // wFormatTag
+
+ // Audio Type I Format
+ FORMAT_TYPE_I_DESCRIPTOR_LENGTH, // bLength
+ INTERFACE_DESCRIPTOR_TYPE, // bDescriptorType
+ SUBCLASS_AUDIOSTREAMING, // bDescriptorSubtype
+ FORMAT_TYPE_I, // bFormatType
+ channel_nb_out, // bNrChannels
+ 0x02, // bSubFrameSize
+ 0x10, // bBitResolution
+ 0x01, // bSamFreqType
+ (uint8_t)(LSB(FREQ_OUT)), // tSamFreq
+ (uint8_t)((FREQ_OUT >> 8) & 0xff), // tSamFreq
+ (uint8_t)((FREQ_OUT >> 16) & 0xff), // tSamFreq
+
+ // Endpoint - Standard Descriptor
+ ENDPOINT_DESCRIPTOR_LENGTH + 2, // bLength
+ ENDPOINT_DESCRIPTOR, // bDescriptorType
+ PHY_TO_DESC(EPISO_IN), // bEndpointAddress
+ E_ISOCHRONOUS, // bmAttributes
+ (uint8_t)(LSB(PACKET_SIZE_ISO_OUT)), // wMaxPacketSize
+ (uint8_t)(MSB(PACKET_SIZE_ISO_OUT)), // wMaxPacketSize
+ 0x01, // bInterval
+ 0x00, // bRefresh
+ 0x00, // bSynchAddress
+
+ // Endpoint - Audio Streaming
+ STREAMING_ENDPOINT_DESCRIPTOR_LENGTH, // bLength
+ ENDPOINT_DESCRIPTOR_TYPE, // bDescriptorType
+ ENDPOINT_GENERAL, // bDescriptor
+ 0x00, // bmAttributes
+ 0x00, // bLockDelayUnits
+ LSB(0x0000), // wLockDelay
+ MSB(0x0000), // wLockDelay
+
+ // Terminator
+ 0 // bLength
+ };
+ return configDescriptor;
+}
+
+uint8_t * USBAudio::stringIinterfaceDesc() {
+ static uint8_t stringIinterfaceDescriptor[] = {
+ 0x0c, //bLength
+ STRING_DESCRIPTOR, //bDescriptorType 0x03
+ 'A',0,'u',0,'d',0,'i',0,'o',0 //bString iInterface - Audio
+ };
+ return stringIinterfaceDescriptor;
+}
+
+uint8_t * USBAudio::stringIproductDesc() {
+ static uint8_t stringIproductDescriptor[] = {
+ 0x16, //bLength
+ STRING_DESCRIPTOR, //bDescriptorType 0x03
+ 'M',0,'b',0,'e',0,'d',0,' ',0,'A',0,'u',0,'d',0,'i',0,'o',0 //bString iProduct - Mbed Audio
+ };
+ return stringIproductDescriptor;
+}