LPC2939设计在MCU USB接口技术的应用

hronize PWM and ADC

Quadrature encoder interface that can monitor one external quadrature encoder

32-bit watchdog with timer change protection, running on safe clock

Up to 152 general-purpose I/O pins with programmable pull-up, pull-down, or bus keeper

Vectored Interrupt Controller （VIC） with 16 priority levels

Up to 22 level-sensitive external interrupt pins, including USB, CAN and LIN wake-up features

Configurable clock-out pin for driving external system clocks

Processor wake-up from Power-down via external interrupt pins and CAN or LIN activity

Flexible Reset Generator Unit （RGU） able to control resets of individual modules

Flexible Clock-Generation Unit （CGU） able to control clock frequency of individual modules:

On-chip very low-power ring oscillator; fixed frequency of 0.4 MHz; always on to provide a Safe_Clock source for system monitoring

On-chip crystal oscillator with a recommended operating range from 10 MHz to 25 MHz. PLL input range 10 MHz to 25 MHz.

On-chip PLL allows CPU operation up to a maximum CPU rate of 125 MHz

Generation of up to 11 base clocks

Seven fractional dividers

Second, dedicated CGU with its own PLL generates USB clocks and a configurable clock output

Highly configurable system Power Management Unit （PMU）：

clock control of individual modules

allows minimization of system operating power consumption in any configuration

Standard ARM test and debug interface with real-time in-circuit emulator

Boundary-scan test supported

ETM/ETB debug functions with 8 kB of dedicated SRAM also accessible for application code and data storage

Dual power supply:

CPU operating voltage: 1.8 V ? 5 %

I/O operating voltage: 2.7 V to 3.6 V; inputs tolerant up to 5.5 V

208-pin LQFP package

图1.LPC2939方框图

图2.LPC2939自供电设备USB接口方框图

图3.LPC2939总线供电设备USB接口方框图

图4.LPC2939 USB OTG端口配置:USB端口1 OTG双任务设备,USB端口2主机

图5.LPC2939 USB OTG端口配置:USB端口1主机,USB端口2主机

图6.LPC2939 USB OTG端口配置:USB端口2设备,USB端口1主机