I've got my boards fab. The board design is based on Stamp reference design. I didnt stuff the whole BOM, instead i am taking it step by step.
I have stuffed
-bf537 dsp ,
-25Mhz crystal with its capacitors and resistors,
-the Rtc with caps and res.
-1.2v switching mosfet with required circuitry.
-Pulled Up NMI
-pulled up reset (have not stuffed reset supervisory ic yet)
-jtag (with required pull ups )
when i power up the board, i can see the pwm on the VROUT pin and can measure 1.2 ~ 1.3 v at VDDINT pin.
-The CLKBUF shows 25Mhz (buffered version of the crystal )
-CLKOUT pin shows nothing, and remains low .
-JTAG does not detect the chip (TDO stuck at high error) (i am using urjtag and wiggler for debugging)
my questions is :
-shouldnt CLKOUT always show some clock on power up ? like CLKBUF , because according to itnernal clock circuitry the CLKBUF and CLKOUT are buffered versions of CLKIN and always on .
-what is JTAG detection of chip dependent on ? jtag is fine as i'v tested it on my other working board. (previous version)-
-should JTAG detect teh chip if we power up the system with no extra periperals but the crystal and the 1.2v circuitry ?