LPC Microcontrollers中的主题 Re: LPC824 Startup time issue

LPC824 Startup time issue

avinashpuli — Thu, 18 May 2017 14:30:30 GMT

Hi , I am using LPC824, In User Manual (UM10800) it is mentioned the startup time from VDD to "user code " is 256us but i am getting around 600us ,In my code i initialized SystemCoreClockUpdate();,Chip_GPIO_Init(LPC_GPIO_PORT); and made gpio output low . can someone help me on this issue to achieve 256us as per datasheet .Thank you

Re: LPC824 Startup time issue

marcprager — Tue, 23 May 2017 14:47:18 GMT

A fair measurement in my opinion would be performing a GPIO without changing clocks.

The initialization you do is already 'your' user code ;-)

Re: LPC824 Startup time issue

kerryzhou — Wed, 24 May 2017 07:17:54 GMT

Hi Avinash Puli,

Agree with Marc, it is not the problem, just caused by your measure method.

SystemCoreClockUpdate();,Chip_GPIO_Init(LPC_GPIO_PORT); already your own user code, it is not include in the startup time.

Your own user code also caused a lot of time.

Wish it helps you!

Have a great day,
Kerry

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------