Hello, here is some more information about the 32kHz oscillator instability/interference theory as the cause for bug #1024.
I have added a way to easily change the setting for the 32kHz oscillator current to the firmware as suggested by Joerg. However here with my devices, it does not change anything. This does not mean a lot, it could be that the documentation for this register is wrong, there is only one place in the documentation which mentions this register and the firmware does not use it so I have no reference. I can measure (or better, estimate ;-) a difference of about 1 uA in the total current of the GSM modem if I change the register setting between highest and lowest oscillator current. I don't know what one could expect here if the setting is correct. There is something else I tried: With one of my GSM Test equipment (HP 8922) I can tune the reference oscillator of the simulated cell. If I change the timing (so far I changed it by 5ppm) in the deep sleep period between receiving the PCH, I get a similar behavior: the error flag is set and it stays set until the phone re-synchronizes. Its not exactly re-camping, but this could come from the fact that my HP 8922 does not have the encryption option and the actual camping to the HP 8922 test cell is a very simple procedure. So maybe this explains the difference. Still, this all is no evidence for anything... Best regards, Dieter _______________________________________________ hardware mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/hardware
