Potential AXI BFM issue

VVC Bitvis VIP AXI
1

The AXI BFM seams to return ‘X’ on read if there is zero hold time of the input data (coming from a slave DUT). The simulation is run using the Xilinx axi_emc IP.

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Line 859 of axi_bfm_pkg.vhd waits for a rising edge of the clock
Response values are collected starting at line 867. At this point in time (with zero hold time) the data is not longer valid (see the screenshot). Note: this is from a behavioral simulation, a post synthesis simulation would always show some (minimal) hold time.

Did somebody else run into this issue?
Should here be an independant response sampleing process that will be used as the response ‘source’?

2

Forget about the initial ‘zero hold idea’. The error is just because of using a wrong variable for creating the log output:

Line 887 of axi_bfm_pkg.vhd: log() uses the wrong variable v_data_value:
log(…to_string(v_data_value…)
changed to:
log(…to_string(rdata_value( 0 to to_integer(unsigned(arlen_value)))…)
make it work.

The v_data_value variable is not used at all. It may be an obstacle from rewriting the code.

Gerald

3

Hi Gerald,

You are right, there is a bug in the log message
We will fix this in the next release.

Regards,
Jørgen