原标题：Digilent Microchip PIC32MX695 chipKIT WF32 Wi-Fi解决方案

　　microchip公司的PIC32MX695F512L是集成了全速USB 2.0 Host/Device/OTG的32位MCU,采用80MHz/105DMIPS的MIPS32 M4K内核,工作电压2.3V-3.6V,工作频率从DC到80MHz. Digilent公司的chipKIT WF32板是基于Arduino™ 开源硬件原型平台,并采用Microchip公司的PIC32MX系列MCU,具有认证的MRF24WG0MA Wi-Fi模块和采用MCP16301 DC/DC转换器的节能的开关电源,以及microSD卡.本文介绍了PIC32MX695F512L主要特性,框图,MIPS32® M4K®处理器内核主要特性和框图,以及评估板chipKIT WF32主要特性,框图,主要元件布局图和电路图.

　　PIC32MX695F512L主要特性:

　　Operating Conditions

　　• 2.3V to 3.6V, -40ºC to +105ºC, DC to 80 MHz

　　Core: 80 MHz/105 DMIPS MIPS32® M4K®

　　• MIPS16e® mode for up to 40% smaller code size

　　• Code-efficient (C and Assembly) architecture

　　• Single-cycle (MAC) 32x16 and two-cycle 32x32 multiply

　　Clock Management

　　• 0.9% internal oscillator

　　• Programmable PLLs and oscillator clock sources

　　• Fail-Safe Clock Monitor (FSCM)

　　• Independent Watchdog Timer

　　• Fast wake-up and start-up

　　Power Management

　　• Low-power management modes (Sleep and Idle)

　　• Integrated Power-on Reset, Brown-out Reset

　　• 0.5 mA/MHz dynamic current (typical)

　　• 41 μA IPD current (typical)

　　Graphics Features

　　• External graphics interface with up to 34 Parallel Master Port (PMP) pins:

　　- Interface to external graphics controller

　　- Capable of driving LCD directly with DMA and internal or external memory

　　Analog Features

　　• ADC Module:

　　- 10-bit 1 Msps rate with one Sample and Hold (S&H)

　　- 16 analog inputs

　　- Can operate during Sleep mode

　　• Flexible and independent ADC trigger sources

　　• Comparators:

　　- Two dual-input Comparator modules

　　- Programmable references with 32 voltage points

　　Timers/Output Compare/Input Capture

　　• Five General Purpose Timers:

　　- Five 16-bit and up to two 32-bit Timers/Counters

　　• Five Output Compare (OC) modules

　　• Five Input Capture (IC) modules

　　• Real-Time Clock and Calendar (RTCC) module

　　Communication Interfaces

　　• USB 2.0-compliant Full-Speed OTG controller

　　• 10/100 Mbps Ethernet MAC with MII and RMII interface

　　• CAN module:

　　- 2.0B Active with DeviceNet™ addressing support

　　• Six UART modules (20 Mbps):

　　- Supports LIN 1.2 protocols and IrDA® support

　　• Up to four 4-wire SPI modules (25 Mbps)

　　• Up to five I2C modules (up to 1 Mbaud) with SMBus support

　　• Parallel Master Port (PMP)

　　Direct Memory Access (DMA)

　　• Up to eight channels of hardware DMA with automatic data size detection

　　• 32-bit Programmable Cyclic Redundancy Check (CRC)

　　• Six additional channels dedicated to USB, Ethernet and CAN modules

　　Input/Output

　　• 15 mA or 10 mA source/sink for standard VOH/VOL and up to 22 mA for non-standard VOH1

　　• 5V-tolerant pins

　　• Selectable open drain and pull-ups

　　• External interrupts

　　Qualification and Class B Support

　　• AEC-Q100 REVG (Grade 2 -40ºC to +105ºC) planned

　　• Class B Safety Library, IEC 60730

　　Debugger Development Support

　　• In-circuit and in-application programming

　　• 4-wire MIPS® Enhanced JTAG interface

　　• Unlimited program and six complex data breakpoints

　　• IEEE 1149.2-compatible (JTAG) boundary scan

　　图1. PIC32MX5XX/6XX/7XX系列框图

　　MIPS32® M4K®处理器内核

　　The MIPS32® M4K® Processor core is the heart of the PIC32MX5XX/6XX/7XX family processor. The CPU fetches instructions, decodes each instruction, fetches source operands, executes each instruction and writes the results of instruction execution to the proper destinations.

　　MIPS32® M4K®处理器内核主要特性:

　　• 5-stage pipeline

　　• 32-bit address and data paths

　　• MIPS32® Enhanced Architecture (Release 2)

　　- Multiply-accumulate and multiply-subtract instructions

　　- Targeted multiply instruction

　　- Zero/One detect instructions

　　- WAIT instruction

　　- Conditional move instructions (MOVN, MOVZ)

　　- Vectored interrupts

　　- Programmable exception vector base

　　- Atomic interrupt enable/disable

　　- GPR shadow registers to minimize latency for interrupt handlers

　　- Bit field manipulation instructions

　　• MIPS16e® code compression

　　- 16-bit encoding of 32-bit instructions to improve code density

　　- Special PC-relative instructions for efficient loading of addresses and constants

　　- SAVE and RESTORE macro instructions for setting up and tearing down stack frames within subroutines

　　- Improved support for handling 8-bit and 16-bit data types

　　• Simple Fixed Mapping Translation (FMT) mechanism

　　• Simple dual bus interface

　　- Independent 32-bit address and data busses

　　- Transactions can be aborted to improve interrupt latency

　　• Autonomous multiply/divide unit

　　- Maximum issue rate of one 32x16 multiply per clock

　　- Maximum issue rate of one 32x32 multiply every other clock

　　- Early-in iterative divide. Minimum 11 and maximum 33 clock latency (dividend (rs) sign extension-dependent)

　　• Power control

　　- Minimum frequency: 0 MHz

　　- Low-Power mode (triggered by WAIT instruction)

　　- Extensive use of local gated clocks

　　• EJTAG debug and instruction trace

　　- Support for single stepping

　　- Virtual instruction and data address/value

　　- Breakpoints

　　- PC tracing with trace compression

　　图2. MIPS32® M4K®处理器内核框图

　　评估板chipKIT WF32

　　The chipKIT WF32 is based on the popular Arduino™ open-source hardware prototyping platform and adds the performance of the Microchip PIC32 microcontroller. The WF32 is the first board from Digilent to have a WiFi MRF24 and SD card on the board both with dedicated signals.The WF32 board takes advantage of the powerful PIC32MX695F512L microcontroller. This microcontroller features a 32-bit MIPS processor core running at 80Mhz, 512K of flash program memory, and 128K of SRAM data memory. The WF32 can be programmed using the Multi-Platform Integrated Development Environment (MPIDE), an environment based on the original Arduino IDE, modified to support PIC32. It contains everything needed to start developing embedded applications. The WF32 features a USB serial port interface for connection to the MPIDE and can be powered via USB or by an external power supply. In addition, the WF32 is fully compatible with the advanced Microchip MPLAB® IDE and works with all MPLAB® compatible in-system programmer/debuggers, such as the Microchip PICkit™3 or the Digilent chipKIT PGM. The WF32 is easy to use and suitable for both beginners and advanced users experimenting with electronics and embedded control systems.

　　评估板chipKIT WF32主要特性:

　　• Microchip® PIC32MX340F512H microcontroller (80 Mhz 32-bit MIPS,512K Flash, 32K SRAM)

　　• compatible with many existing Arduino code samples and other resources

　　• Arduino Uno form factor

　　• compatible with many Arduino shields

　　• 42 available I/O pins

　　• two user LEDs

　　• PC connection uses a USB A > mini B cable (not included)

　　• 12 analog inputs

　　• 3.3V operating voltage

　　• 80Mhz operating frequency

　　• 75mA typical operating current

　　• 7V to 15V input voltage (recommended)

　　• 20V input voltage (maximum)

　　• 0V to 3.3V analog input voltage range

　　• +/-18mA DC current per pin

　　图3. 评估板chipKIT WF32外形图

　　图4. 评估板chipKIT WF32主要元件分布图

　　评估板chipKIT WF32主要元件说明: