ADuC7026 datasheet says about pin#20 (BM/P0.0/CMPOUT/PLAI/MS0):
The ADuC7026/ADuC7027 enter UART download mode if BM is low at reset
and execute code if BM is pulled high at reset through a 1 kΩ resistor
But our eval board seems not follow with this instruction, it seems just leave NC or pull down by SW2 when entering UART download mode.
I suppose EVAL design is for general (some customer use as GPIO or other function). That's why BM pin just leave NC.
But depend on user case, BM pin should be pull up to ensure ADuC7026 exactly execute code.
My understanding is correct?
Thank you for your help as always.