锁相环用于电机转速精准检测，资料很不错，值得下载-Phase-locked loop for accurate detection of motor speed

LPC213x系列底层硬件驱动函数库，包含：GPIO、UART、I2C、SPI、SSP、PWM、定时计数器、ADC、DA、实时时钟、看门狗、中断控制器、锁相环PLL、IAP等，有使用说明和源码分析。-LPC213x series of underlying hardware driver library, including: GPIO, UART, I2C, SPI, SSP, PWM, timer counter, ADC, DA, real-time clock, watchdog, in

用Verilog HDL编写的锁相环程序-Phase-locked loop program written in Verilog HDL