https://community.nxp.com/t5/LPC-Microcontrollers/LPC55S69-%E5%A6%82%E4%BD%95%E4%BD%BF%E7%94%A8DWT%E5%AE%9E%E7%8E%B0us%E5%BB%B6%E6%97%B6/m-p/1610804#M51829 <P>Hi</P> <P>Yes, enabling SDK_DELAY_USE_DWT and DWT is enough.</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="ZhangJennie_0-1678183086037.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/213522i105E6DD25C23F1F1/image-size/medium?v=v2&amp;px=400" role="button" title="ZhangJennie_0-1678183086037.png" alt="ZhangJennie_0-1678183086037.png" /></span></P> <P>&nbsp;</P> <P>Have a nice day,</P> <P>Jun Zhang</P> Tue, 07 Mar 2023 09:58:21 GMT ZhangJennie 2023-03-07T09:58:21Z https://community.nxp.com/t5/LPC-Microcontrollers/LPC55S69-%E5%A6%82%E4%BD%95%E4%BD%BF%E7%94%A8DWT%E5%AE%9E%E7%8E%B0us%E5%BB%B6%E6%97%B6/m-p/1610660#M51824 <P>在fsl_common_arm.c库文件中有一个函数：void SDK_DelayAtLeastUs(uint32_t delayTime_us, uint32_t coreClock_Hz)。但要实现精准的us延时把DWT打开，定义#define SDK_DELAY_USE_DWT 1。下图两个位置的函数都运行，但误差还是很大？除了打开SDK_DELAY_USE_DWT宏外，还需要更改其它地方嘛？</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="wangyibin_0-1678174965690.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/213483i8FE6888111D7F6B3/image-size/medium?v=v2&amp;px=400" role="button" title="wangyibin_0-1678174965690.png" alt="wangyibin_0-1678174965690.png" /></span></P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="wangyibin_1-1678174990550.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/213484iC4F4A9510B3EB4F0/image-size/medium?v=v2&amp;px=400" role="button" title="wangyibin_1-1678174990550.png" alt="wangyibin_1-1678174990550.png" /></span></P><P>&nbsp;</P> Tue, 07 Mar 2023 07:45:01 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC55S69-%E5%A6%82%E4%BD%95%E4%BD%BF%E7%94%A8DWT%E5%AE%9E%E7%8E%B0us%E5%BB%B6%E6%97%B6/m-p/1610660#M51824 wangyibin 2023-03-07T07:45:01Z https://community.nxp.com/t5/LPC-Microcontrollers/LPC55S69-%E5%A6%82%E4%BD%95%E4%BD%BF%E7%94%A8DWT%E5%AE%9E%E7%8E%B0us%E5%BB%B6%E6%97%B6/m-p/1610804#M51829 <P>Hi</P> <P>Yes, enabling SDK_DELAY_USE_DWT and DWT is enough.</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="ZhangJennie_0-1678183086037.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/213522i105E6DD25C23F1F1/image-size/medium?v=v2&amp;px=400" role="button" title="ZhangJennie_0-1678183086037.png" alt="ZhangJennie_0-1678183086037.png" /></span></P> <P>&nbsp;</P> <P>Have a nice day,</P> <P>Jun Zhang</P> Tue, 07 Mar 2023 09:58:21 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC55S69-%E5%A6%82%E4%BD%95%E4%BD%BF%E7%94%A8DWT%E5%AE%9E%E7%8E%B0us%E5%BB%B6%E6%97%B6/m-p/1610804#M51829 ZhangJennie 2023-03-07T09:58:21Z