【摘要】 在车辆ASR系统开发中,提出了基于HCS12单片机增强型定时器复用I/O输出PWM信号的开发方案,解决了由于硬件限制导致PWM输出通道的不足的问题。介绍了单片机增强定时器通过输出比较寄存器、输出比较中断、TCNT输出翻转实现PWM波形输出的3种方法,详述了各方法中重要寄存器的设置和逻辑对应关系,并给出了相应的波形输出图和程序流程图,通过理论分析和实验结果探讨了不同设计方案的优缺点。更多还原

【Abstract】 The development of multiplex I/O output PWM waveform based on enhanced capture timer module of HSC12 single-chip is proposed in vehicle ASR system,to solves PWM output channels shortage due to hardware limitation led to the problem.Three approaches taken in the investigation is called output-compare register,interrupt caused by output-compare and TCNT output flip.Details of the methods set the single-chip registers and logical corresponding relation is introduced,the waveform output map and the procedure-flow chart is given.The character of different designs is proposed and the limitation is researched according to theory analysis the experimental results.更多还原