Hi, We have built a prototype board (Based on sensor tag design) with CC2541 and a couple of temperature sensors (TMP006, LM92) on it.
CC-Debugger can see the CC2541, and also program it. But we are not able to see the clock coming out of the crystal.
We are using 32MHz TXC crystal (http://www.txccrystal.com/images/pdf/7b-accuracy.pdf). Crystal has a load capacitance of 10pF; and Equivalent Seires Resistance (ESR) of 40 ohm.
We have tried 12pF, 18pF, 22pF on leg capacitance.
[Based on the formula C1*C2 / C1+C2; and with TI recommends, I think we covered the range on leg capacitance]
AVDDx, DVDD were at 2.4V. No clock is seen on Pin 22/23 (XOSC_Q1/XOSC_Q2).
Please help see if this is not the right crystal, or if there is a recommended list of crystals with correct leg capacitance that will work with CC2541.
From the software standpoint, after downloading and starting execution, code can execute write to SLEEPCMD :
SLEEPCMD &= ~OSC_PD; /* start 16MHz RCOSC & 32MHz XOSC */
but after that it is not able to get XOSC_STB in SLEEPSTA register. Basically gets stuck in loop at
while(!(SLEEPSTA & XOSC_STB));
Value of SLEEPSTA is 0x2C.
Appreciate your help!
Thank you very much.
Jay.