CC2650: about the clock source at CC2650's simple peripheral example ?

Dimitrios Karoutsos

Part Number: CC2650

Hello,

I'm trying to understand how my CC2650's custom board, runs the firmware even if I remove the 24 MHz crystal from PCB.

I downloaded the Simple_Peripheral example from resource explorer. I modified it to blink a LED on my custom board. The led is blink as expected but the device do not advertise, Next, I found that the 24MHz crystal do not oscillating. I remove the 24MHz crystal from PCB and try to run my project, the LED is blinking again!!

So, How the CC2650 can run the firmware without HF crystal oscillator? Notice that, i did not edit the configuration, by the default Simple_Peripheral example is set use 24MHz Crystal Oscillator.

over 9 years ago

0 Eirik V over 9 years ago

TI__Guru 56590 points

Hello Dimitrios,

When no radio operations are required the board can be clocked by the on-chip HSRCOSC which runs at 48 MHz. For all radio operations you will need a higher accuracy clock than the HSRCOSC and hence you need a functional 24 MHz XTAL to run any radio operations.

Have you gone through the HW checklist at ti.com/ble-wiki:

Bluetooth®︎

Bluetooth forum

CC2650: about the clock source at CC2650's simple peripheral example ?