I had made a new ADSP-21489 board with 25MHz crystal on DSP pin 24 & 25, and I couldn't use HPUSB-ICE to access it through JTAG port. But when I changed the crystal to 4MHz, I can run the example code "LedBlink" in the target board with ICE. What's wrong with my DSP board?
I also found the SDRAM clock out (SDQM) was not good, it seems not as stable as the ADSP-21489 EZ Board's same pin output. I can't measure the real output frequency, but EZ board was very clear 200MHz.
By the way, I tried to run other example code in 4MHz, it will stop when running the PLL access code.
My DSP board only used SDRAM, and some ADC/DAC, no SRAM, no FLASH, no watchdog, no temperature device.
No used pins was left floating.
VDDINT = 3.29V
VDDEXT = 1.09V
RESET pin = 3.29V
Is there anything I should pay attention to?