System Verilog Assertions - Nonconsecutive Repetition

Nonconsecutive Repetition : - Repeated, Nonconsecutive Boolean expressions can be defined using [=N] - Nonconsecutive - Not necessarily consecutive - Syntax : expr[=N]; expr must occur N times - Example : When A is high then from the same cycle , there must be two cycles of B before C ...

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System Verilog Assertions - Consecutive Repetition

Consecutive Repetition : - Repeated, consecutive sequences can be defined using [*N] - Syntax : SEQ[*N]; SEQ, repeated N times - Example : A is never low for more than 4 cycles property CONSECUTIVE_REPET; @(negedge...

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System Verilog Assertions - How it Works !!!

Here, is the flow diagram of how an assertion gets evaluated - Syntax : @(Clocking) disable iff (EXPR) enabling_sequence |=> fulfilling_sequence...

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System Verilog Assertions - Sequences

System Verilog Sequences : - Temporal properties are described using sequences - Series of Boolean equations - Each cycle separated by ## - Syntax : SEQ_A |-> SEQ_B OR SEQ_A |=> SEQ_B - Properties are either unconditional using instantaneous Boolean expression ...

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System Verilog Assertions - Example Problem

Problem: Write assertion(s) to verify the behavior of the below circuit - Solution:...

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System Verilog Assertions - Useful Built-in Functions

$past() : - Returns the value of a signal from previous evaluation cycle - Syntax : $past (A, N) ; Default N = 1 - Example : property PAST1; @(negedge CLK) EN |-> (OP == $past(IP , 2 )); endproperty ...

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System Verilog Assertions - Assertion Overlapping

Assertion Overlapping : - Assertions are checked at every evaluation point. - If the start condition is true, a new assertion is triggered. - Many copies of an assertion may be active simultaneously. Example : property A0; @(negedge CLK) REQ |=>...

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System Verilog Assertions - Example Problem

Lets have a look at below FSM Design - DATA_VALID is an input signal. DATA_READ is an output signal.Write assertions to verify the state transition from current state and inputs and outputs from current states. ( Hint: Use Implication Operators)Solution...

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System Verilog Assertions - Implication Operators

Same Cycle Implication ( |->) : Only under certain conditions assertions may be valid. exp1 |-> exp2 ; If exp1 is true then exp2 must be true at the same evaluation point.Example : property SameCyImp ...

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System Verilog Assertions - Clocked Property Evaluation

Clocked Property Evaluation : Remember - "Objects are sampled before the Clock Edge"Lets have a look at below examples -1) property EN_1HOT @(EN1 or EN2) (EN1 | EN2) endproperty 2) property EN_1HOT_CLK @(psoedge CLK) (EN1 | EN2) endproperty Now, Lets have a look at the signal...

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System Verilog Assertions - Counterintuitive Clock Behavior

Counterintuitive Clock Behavior in Assertions: It is possible that the properties do not behave as intended. Example : Using the same signal in clocking expression and the property definition assert property (@(posedge clock) clock))...

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System Verilog Assertions - Simple Boolean Assertions

There are two kind of assertions in System Verilog :1) Immediate Assertion (Assert)2) Concurrent Assertion (Assert Property)1) Immediate Assertion: These are procedural statements (Embedded within a procedural block) and only active within the block. These are similar to the 'if' statement. Example : always @ (negedge clock ) assert !(wr_en...

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System Verilog Assertions - What & Why & Who

Assertion:What : A check embedded in the code !!! Embedded in functional code, ignored by synthesis !!!Why : 1) To check if - a) A specific condition occurs during the simulation or b) A specific sequence of events occurs ...

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