Hi, we made our first printed circuit board with BF703 and found out a boot stream can't be loaded via UART at speeds above 57600. At a speed of 115200 the device returns <DF 89 00 80> as a response on '@' instead of the expected <BF xx xx 00>. Is this some error in our board or a boot stream just can't be loaded at a speed of 115200? The speed is supported by a BF707 evaluation kit. A crystal oscillator - 24 MHz; dividers are standard. UART clock - 18 MHz (judging by returned dividers); signal edges of '@' are accurate (was checked by a oscilloscope).
Yes, if the UART speed is not greater than 57600 the device responds correctly:
9600 -> <BF 75 00 00> - multicard and motherboard 19200 -> <BF 3A 00 00> - multicard and motherboard 38400 -> <BF 1D 00 00> - multicard and motherboard 57600 -> <BF 13 00 00> - multicard and motherboard115200 -> <DF 89 00 80> - multicard115200 -> <DF 22 20 F0> - motherboard
multicard - VScom PCI200L multicard port
motherboard - PC motherboard port
The part number of BF703: