I do not see any output from a UART 16550 in my MicroBlaze, Virtex-5 system. What is the problem?
Typically, the issue of not seeing any output from a UART is due to a baud rate. However, when the baud is correctly set, and you still do not see any output, this problem has been traced to using the hardware multiplier in the MicroBlaze.
1. Right-click on the MicroBlaze instance in your system and select Configure IP.
2. From the Instructions tab, deselect Enable Integer Multiplier. This setting is equivalent to the C_USE_HW_MUL parameter.
3. Click OK.
For the change to take affect, the hardware and software needs to be rebuilt.
Please refer to (Xilinx Answer 24006), if the hardware multiplier is required.