CC2538: Inquiry about Power-up sequence

Takayuki Miyazaki

Part Number: CC2538
Other Parts Discussed in Thread: CC2592, Z-STACK

Hi Experts,

I got inquiries about CC2538 power-up sequence from our customer. Our customer is developing something like module with CC2538/CC2592. I attached the simple circuit diagram (CC2538_PowerUp_Sequence.pptx).

1. Which of the points A or point B in Fig.2 does the crystal start?

1-1.If point A is correct, is Customer able to understand there is not any issue if there is enough crystal stabilization time ?

1-2. If point B is correct, Should customer require time which CC2538 is stable ? How long should customer wait for this time? Does it depend on crystal which customer used?

Best regards,

Miyazaki

over 4 years ago

0 TER over 4 years ago

TI__Guru**** 317180 points

The answer is dependent on how the device is used.

If you look at "7.2.1 High Frequency Oscillators" in http://www.ti.com/lit/ug/swru319c/swru319c.pdf you see that dependent on the register setting the device can run on the RCOSC until the xtal is up.

Also note that when the chip is in active reset nothing is running. The xtal will start after the reset is released.

If they are running the Z-stack provided by TI the start-up is taken into account.

0 Takayuki Miyazaki over 4 years ago in reply to TER

TI__Genius 10120 points

Hello TER,

Thanks for clarification. I tried to check Z-stack and remembered CC253x was waiting until XOSC_STB bit was set.

Thanks again and best regards,

Miyazaki

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CC2538: Inquiry about Power-up sequence