美芯18F87J50 USB插入模块解决方案

Microchip公司的PIC18F87J50 FS USB插入模块(PIM)可以用来评估Microchip的全速USB PIC18F87J50系列微控制器，PIM可单独使用，也可和HPC Explorer板组合使用．这些器件支持USB 2.0全速和低速串行通信，信号速率为12Mbps 或1.5Mbps.本文所提供的硬件电路图和软件，能使设计者开发出可选择性的USB通信解决方案．

PIC18F87J50 FS USB Plug-In Module
The PIC18F87J50 FS USB Plug-In Module (PIM) Demonstration Board and Kit is designed as an easy-to-use evaluation platform for Microchip’s Full-Speed USB PIC18F87J50 family of microcontrollers. The PIM may be operated either stand-alone, or in conjunction with the HPC Explorer board (microchipDIRECT part number DM183022).

These devices fully support USB 2.0 full-speed and low-speed serial communications
at signaling speeds of 12 Mbit/s or 1.5 Mbit/s. The demonstration kit provides all of the
hardware and software needed to develop officially compliant USB communication solutions.

The Demonstration Kit contains the following items:
1. The PIC18F87J50 FS USB Plug-In Module demonstration board, preprogrammed with USB Human Interface Device (HID) class mouse demonstration firmware.
2. A standard USB mini-B cable for power and communication.
3. The PICDEM. FS USB Starter Kit CD-ROM, containing USB firmware projects, Microchip’s custom class USB driver and USB-specific documentation, such as this user’s guide.
下面是PIC18F87J50 系列的主要性能介绍：
64/80-Pin High-Performance,1-Mbit Flash USB Microcontrollers with nanoWatt Technology

USB特性:
USB V2.0 Compliant SIE
Low Speed (1.5 Mb/s) and Full Speed (12 Mb/s)
Supports Control, Interrupt, Isochronous and Bulk Transfers
Supports up to 32 Endpoints (16 bidirectional)
3.9-Kbyte Dual Access RAM for USB
On-Chip USB Transceiver

灵活的振荡器架构:
High-Precision PLL for USB
Two External Clock modes, up to 48 MHz
Internal 31 kHz Oscillator, Tunable Internal Oscillator, 31 kHz to 8 MHz
Secondary Oscillator using Timer1 @ 32 kHz
Fail-Safe Clock Monitor:
Allows for safe shutdown if any clock stops

外设特性:
High-Current Sink/Source 25 mA/25mA (PORTB and PORTC)
Four Programmable External Interrupts
Four Input Change Interrupts
Two Capture/Compare/PWM (CCP) modules
Three Enhanced Capture/Compare/PWM (ECCP) modules:
One, two or four PWM outputs
Selectable polarity
Programmable dead time
Auto-shutdown and auto-restart
Two Master Synchronous Serial Port (MSSP) modules supporting 3-Wire SPI (all 4 modes) and I2C. Master and Slave modes
8-Bit Parallel Master Port/Enhanced Parallel Slave Port with 16 Address Lines
Dual Analog Comparators with Input Multiplexing
10-Bit, up to 12-Channel Analog-to-Digital (A/D) Converter module:
Auto-acquisition capability
Conversion available during Sleep
Two Enhanced USART modules:
Supports RS-485, RS-232 and LIN 1.2
Auto-wake-up on Start bit
Auto-Baud Detect
外接存储器总线(80-pin devices only):
Address Capability of up to 2 Mbytes
8-Bit or 16-Bit Interface
12-Bit, 16-Bit and 20-Bit Addressing modes

专用微控制器特性:
5.5V Tolerant Inputs (digital-only pins)
Low-Power, High-Speed CMOS Flash Technology
C Compiler Optimized Architecture for Re-Entrant Code

Power Management Features:
- Run: CPU on, peripherals on
- Idle: CPU off, peripherals on
- Sleep: CPU off, peripherals off
Priority Levels for Interrupts
Self-Programmable under Software Control
8 x 8 Single-Cycle Hardware Multiplier

Extended Watchdog Timer (WDT):
- Programmable period from 4 ms to 131s
Single-Supply In-Circuit Serial Programming (ICSP.) via Two Pins
In-Circuit Debug (ICD) with 3 Breakpoints via Two Pins
Operating Voltage Range of 2.0V to 3.6V
On-Chip 2.5V Regulator
Flash Program Memory of 10000 Erase/Write Cycles and 20-Year Data Retention
下图是PIC18F8XJ5X (80-PIN) 方框图：



下图是PIC18F87J50系列时钟方框图：



PIC18F87J50系列USB功能简介：
The PIC18F87J50 microcontroller is the .superset. device in the PIC18F87J50 microcontroller
family. The PIC18F87J50 has the highest memory and pin count in the family, but otherwise shares an identical feature set (except features which require pins not present on 64-pin devices) compared to the other devices. All of the devices in the family are code-compatible with each other and share the same USB capabilities:
USB 2.0 compliance
Full-speed (12 Mbit/s) and low-speed (1.5 Mbit/s) operation
Support of control, interrupt, bulk and isochronous transfers
Support of up to 32 endpoints
3.9 Kbytes of dual access RAM for USB or general purpose use
On-chip features for a single chip USB implementation, including:
- USB Serial Interface Engine (SIE)
- USB transceiver
- USB pull-up resistors
- D+ and D- driver output impedance matching resistors
USING THE PREPROGRAMMED FIRMWARE
The PIC18F87J50 FS USB Plug-In Module comes preprogrammed with HID class firmware. Upon plugging in the USB cable to a Windows® operating system based host PC, the device should automatically enumerate as a HID class mouse. The mouse cursor should promptly begin moving around in a continuous circular pattern, and the red LEDs on the PIM should begin blinking in an alternate manner. To stop the mouse cursor from moving, simply press the .S4. push button located in the lower right corner of the PIM. If the LEDs fail to illuminate, the device fails to enumerate or the mouse does not move in a circle, verify that jumpers, JP4 and JP5, are installed. See Figure 3-1 for the locations of these components.



图３．PIC18F87J50 FS USB PIM REV. 1电路图(1/2)