3
0
Fork 0
mirror of https://github.com/YosysHQ/yosys synced 2025-04-06 17:44:09 +00:00
yosys/frontends
Jannis Harder a855d62b42 verific: Improve logic generated for SVA value change expressions
The previously generated logic assumed an unconstrained past value in
the initial state and did not handle 'x values. While the current formal
verification flow uses 2-valued logic, SVA value change expressions
require a past value of 'x during the initial state to behave in the
expected way (i.e. to consider both an initial 0 and an initial 1 as
$changed and an initial 1 as $rose and an initial 0 as $fell).

This patch now generates logic that at the same time

	a) provides the expected behavior in a 2-valued logic setting, not
	   depending on any dont-care optimizations, and

	b) properly handles 'x values in yosys simulation
2022-05-09 15:04:01 +02:00
..
aiger Fixing old e-mail addresses and deadnames 2021-06-08 00:39:36 +02:00
ast sv: fix always_comb auto nosync for nested and function blocks 2022-04-05 14:43:48 -06:00
blif Fixing old e-mail addresses and deadnames 2021-06-08 00:39:36 +02:00
json fix handling of escaped chars in json backend and frontend 2022-02-18 17:13:09 +01:00
liberty Fixing old e-mail addresses and deadnames 2021-06-08 00:39:36 +02:00
rpc Fix argument handling in connect_rpc 2020-10-19 13:40:57 +02:00
rtlil Specify minimum bison version 3.0+ 2021-10-01 21:18:33 -06:00
verific verific: Improve logic generated for SVA value change expressions 2022-05-09 15:04:01 +02:00
verilog verilog: support for time scale delay values 2022-02-14 15:58:31 +01:00