Microchip公司的PIC32Mx系列32位MCU采用MIPS32® M4K® 32位RISC内核,具有5级流水线,最大工作频率80MHz,它集成的MCU具有32K到512KB闪存,8KB-32KB SRAM,具有多个功率管理模式,引脚和大多数的PIC24/dsPIC® DSC兼容.器件集成了多种外设,其模拟特性包括多达16路的10位ADC和两个模拟比较器.PIC32 MCU可用在从控制逻辑到集成系统等多种用处.而采用PIC32M的音频开发板是24位音频录音和播放,USB数字音频,MP3译码和取样速率转换的灵活平台,可用在汽车信息娱乐和便携式音频设备.本文介绍了PIC32MX3XX/4XX主要特性,方框图以及音频开发板主要特性,主要元器件,电路图和元件布局图.

Microchip’s 32-bit portfolio with the MIPS® M4K® offers high performance microcontrollers, and all the tools needed to develop your embedded project. With free software, low cost development tools, and pin/peripheral compatibility from 16-bit product lines, PIC32 MCUs shorten time to market and allow your designs to grow. PIC32 gives your application the processing power, memory and peripherals your design needs! 32-bit PIC® microcontrollers are well suited for a wide variety of applications from control logic, to fully integrated systems involving USB, Ethernet and LCD.

PIC32MX3XX/4XX主要特性:
High-Performance, General Purpose and USB, 32-bit Flash Microcontrollers High-Performance 32-bit RISC CPU:
• MIPS32® M4K® 32-bit core with 5-stage pipeline
• 80 MHz maximum frequency
• 1.56 DMIPS/MHz (Dhrystone 2.1) performance at 0 wait state Flash access
• Single-cycle multiply and high-performance divide unit
• MIPS16e® mode for up to 40% smaller code size
• Two sets of 32 core register files (32-bit) to reduce interrupt latency
• Prefetch Cache module to speed execution from Flash
Microcontroller Features:
• Operating temperature range of -40ºC to +105ºC
• Operating voltage range of 2.3V to 3.6V
• 32K to 512K Flash memory (plus an additional 12 KB of boot Flash)
• 8K to 32K SRAM memory
• Pin-compatible with most PIC24/dsPIC® DSC devices
• Multiple power management modes
• Multiple interrupt vectors with individually programmable priority
• Fail-Safe Clock Monitor Mode
• Configurable Watchdog Timer with on-chip Low-Power RC Oscillator for reliable operation
Peripheral Features:
• Atomic SET, CLEAR and INVERT operation on select peripheral registers
• Up to 4-channel hardware DMA with automatic data size detection
• USB 2.0-compliant full-speed device and On-The-Go (OTG) controller
• USB has a dedicated DMA channel
• 3 MHz to 25 MHz crystal oscillator
• Internal 8 MHz and 32 kHz oscillators
• Separate PLLs for CPU and USB clocks
• Two I2C™ modules
• Two UART modules with:
- RS-232, RS-485 and LIN support
- IrDA® with on-chip hardware encoder and decoder
• Up to two SPI modules
• Parallel Master and Slave Port (PMP/PSP) with 8-bit and 16-bit data and up to 16 address lines
• Hardware Real-Time Clock and Calendar (RTCC)
• Five 16-bit Timers/Counters (two 16-bit pairs combine to create two 32-bit timers)
• Five capture inputs
• Five compare/PWM outputs
• Five external interrupt pins
• High-Speed I/O pins capable of toggling at up to 80 MHz
• High-current sink/source (18 mA/18 mA) on all I/O pins
• Configurable open-drain output on digital I/O pins Debug Features:
• Two programming and debugging Interfaces:
- 2-wire interface with unintrusive access and real-time data exchange with application
- 4-wire MIPS® standard enhanced JTAG interface
• Unintrusive hardware-based instruction trace
• IEEE Standard 1149.2-compatible (JTAG) boundary scan
Analog Features:
• Up to 16-channel 10-bit Analog-to-Digital Converter:
- 1000 ksps conversion rate
- Conversion available during Sleep, Idle
• Two Analog Comparators

图1. PIC32MX3XX/4XX系列方框图

音频开发板
The audio development board for PIC32 (DM320011) provides developers a flexible platform for 24-bit audio record and playback, USB Digital Audio, MP3 Decode and Sample Rate Conversion.

音频开发板主要特性:
- On-board PIC32MX795F512 with 80 MIPS of performance, 512KB Flash and 128KB of RAM
- 24-bit Wolfson CODEC
- USB Type A interface
- On-board Microphone
- Headphone out and Line in
- High quality 2” Color LCD
- Pre-loaded demo code
- MFi Dock Edge Connector

图2. PIV32 MCU音频开发板外形图
音频开发板元件描述:


图3.音频开发板电路图:显示器电路

图4.音频开发板电路图:音频电路

图5.音频开发板电路图:MCU和USB电路

图6.音频开发板电路图:电源电路

图7.音频开发板电路图:通信电路(扩展连接器,ICSP,开关和LED)

图8.音频开发板布局图