BF537 Jtag not detecting

Hi,

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 ?

Parents Reply Children
No Data