LPC824 Startup time issue

[avinashpuli]

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

[kerryzhou]

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

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[marcprager]

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

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