Assertion logic

SystemVerilog
1

A STUFF ERROR has to be detected at the bit time of the 6 consecutive equal bit level in a message field .

means 5 consecutive bit are 1 than 6th bit should be 0 vice versa also.
please help me how to write property for above logic in assertion

2

In reply to raj@123:

  bit clk, signal;
   
   property stuff(value, repetition );
      @(posedge clk) value[* repetition] |-> ##1 !(value);
   endproperty
   stuff_0: assert property (stuff(signal==1,5));
   stuff_1: assert property (stuff(signal==0,5));
3

In reply to dave_59:

 property bit_stuffing_on_diffrent_field_of_remote_frame(1,5);
	@(posedge (phase_seg2))  1[*5] |-> ##1  !(1);
  endproperty
	
stuff1: assert property (bit_stuffing_on_diffrent_field_of_remote_frame(intf.CAN_H==1,5));
stuff0: assert property (bit_stuffing_on_diffrent_field_of_remote_frame(intf.CAN_H==0,5));


	begin
        `disp_ast"  VALID FRAME WITHOUT STUFF  ");
		 	end
	else
	begin
	`TC_CAN_ASSERTION_E_003
	end
	
	cov_bit_stuff: cover property(bit_stuffing_on_diffrent_field_of_remote_frame);

this one throuhinh error let me know what is mistake here .

  • at /tru/shubhams/Workspace/tc_can_vip/common/src/tc_can_assertions.sv(226): near “1”: syntax error, unexpected INTEGER NUMBER, expecting ‘)’.
4

In reply to raj@123:

Are you trying to compile the same code?

bit_stuffing_on_diffrent_field_of_remote_frame**(1,5)**
can integer be there in property’s argument declaration? shouldn’t it be a variable?


  property bit_stuffing_on_diffrent_field_of_remote_frame(1,5); //shouldn't (1,5) be variable?
	@(posedge (phase_seg2))  1[*5] |-> ##1  !(1);           //!(1) -> how will this be true at any point of time?
  endproperty
5

In reply to raj@123:

Basic, issue seems to me.

  1. You can not use number as variable name.
  2. for consicutive repetitions seq or signal only used. You can’t use direct number.

  // Number are not allowed as variable name
  property bit_stuffing_on_diffrent_field_of_remote_frame(1,5);

  // You need to change your code as per Dave's.
  property bit_stuffing_on_diffrent_field_of_remote_frame(value, repetitions);

Thanks!