03-29-2012 01:34 PM
03-29-2012 03:24 PM - edited 03-29-2012 03:25 PM
Often, people are confused by the MicorBlaze reset: is it positive true, or negative true? Seems your design has it flipped somewhere, and it is saying it can't run (being held in reset). Read the manual, check the source of the reset signal.
03-29-2012 04:31 PM
Yup. The reset line is connected to a pull-up, while mb_reset is active high, so that is perhaps the problem. How do I fix it, preferably from either the XPS GUI or by changing the Board Support Package?
03-29-2012 05:26 PM
Your .mhs file should have a line like this in it:
PORT fpga_0_rst_1_sys_rst_pin = sys_rst_s, DIR = I, SIGIS = RST, RST_POLARITY = 1
You should be able to change the reset polarity by flipping the value of RST_POLARITY between 1 and 0.
03-31-2012 10:07 AM
I tried that, but I get an error: "Parameter C_EXT_RESET_HIGH is set to 0 while input reset port is connected to an ACTIVE_HIGH reset."
I does occur to me, though, that it is easy to put an inverter on the reset line in the board support description file. Many of the vendor-supplied .XBD files do this.
04-02-2012 08:44 AM
Update - closer inspection of the .xbd file reveals that both the reset and the clock are connected up wrong. It was clearly written by an idiot (me).