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// Copyright lowRISC contributors.
// Licensed under the Apache License, Version 2.0, see LICENSE for details.
// SPDX-License-Identifier: Apache-2.0
// Macros and helper code for using assertions.
// - Provides default clk and rst options to simplify code
// - Provides boiler plate template for common assertions
`ifndef PRIM_ASSERT_SV
`define PRIM_ASSERT_SV
///////////////////
// Helper macros //
///////////////////
// Default clk and reset signals used by assertion macros below.
`define ASSERT_DEFAULT_CLK clk_i
`define ASSERT_DEFAULT_RST !rst_ni
// Converts an arbitrary block of code into a Verilog string
`define PRIM_STRINGIFY(__x) `"__x`"
// ASSERT_ERROR logs an error message with either `uvm_error or with $error.
//
// This somewhat duplicates `DV_ERROR macro defined in hw/dv/sv/dv_utils/dv_macros.svh. The reason
// for redefining it here is to avoid creating a dependency.
`define ASSERT_ERROR(__name) \
`ifdef UVM \
uvm_pkg::uvm_report_error("ASSERT FAILED", `PRIM_STRINGIFY(__name), uvm_pkg::UVM_NONE, \
`__FILE__, `__LINE__, "", 1); \
`else \
$error("%0t: (%0s:%0d) [%m] [ASSERT FAILED] %0s", $time, `__FILE__, `__LINE__, \
`PRIM_STRINGIFY(__name)); \
`endif
// This macro is suitable for conditionally triggering lint errors, e.g., if a Sec parameter takes
// on a non-default value. This may be required for pre-silicon/FPGA evaluation but we don't want
// to allow this for tapeout.
`define ASSERT_STATIC_LINT_ERROR(__name, __prop) \
localparam int __name = (__prop) ? 1 : 2; \
always_comb begin \
logic unused_assert_static_lint_error; \
unused_assert_static_lint_error = __name'(1'b1); \
end
// Static assertions for checks inside SV packages. If the conditions is not true, this will
// trigger an error during elaboration.
`define ASSERT_STATIC_IN_PACKAGE(__name, __prop) \
function automatic bit assert_static_in_package_``__name(); \
bit unused_bit [((__prop) ? 1 : -1)]; \
unused_bit = '{default: 1'b0}; \
return unused_bit[0]; \
endfunction
// The basic helper macros are actually defined in "implementation headers". The macros should do
// the same thing in each case (except for the dummy flavour), but in a way that the respective
// tools support.
//
// If the tool supports assertions in some form, we also define INC_ASSERT (which can be used to
// hide signal definitions that are only used for assertions).
//
// The list of basic macros supported is:
//
// ASSERT_I: Immediate assertion. Note that immediate assertions are sensitive to simulation
// glitches.
//
// ASSERT_INIT: Assertion in initial block. Can be used for things like parameter checking.
//
// ASSERT_INIT_NET: Assertion in initial block. Can be used for initial value of a net.
//
// ASSERT_FINAL: Assertion in final block. Can be used for things like queues being empty at end of
// sim, all credits returned at end of sim, state machines in idle at end of sim.
//
// ASSERT: Assert a concurrent property directly. It can be called as a module (or
// interface) body item.
//
// Note: We use (__rst !== '0) in the disable iff statements instead of (__rst ==
// '1). This properly disables the assertion in cases when reset is X at the
// beginning of a simulation. For that case, (reset == '1) does not disable the
// assertion.
//
// ASSERT_NEVER: Assert a concurrent property NEVER happens
//
// ASSERT_KNOWN: Assert that signal has a known value (each bit is either '0' or '1') after reset.
// It can be called as a module (or interface) body item.
//
// COVER: Cover a concurrent property
//
// ASSUME: Assume a concurrent property
//
// ASSUME_I: Assume an immediate property
`ifdef VERILATOR
`include "prim_assert_dummy_macros.svh"
`elsif SYNTHESIS
`include "prim_assert_dummy_macros.svh"
`elsif YOSYS
`include "prim_assert_yosys_macros.svh"
`define INC_ASSERT
`else
`include "prim_assert_standard_macros.svh"
`define INC_ASSERT
`endif
//////////////////////////////
// Complex assertion macros //
//////////////////////////////
// Assert that signal is an active-high pulse with pulse length of 1 clock cycle
`define ASSERT_PULSE(__name, __sig, __clk = `ASSERT_DEFAULT_CLK, __rst = `ASSERT_DEFAULT_RST) \
`ASSERT(__name, $rose(__sig) |=> !(__sig), __clk, __rst)
// Assert that a property is true only when an enable signal is set. It can be called as a module
// (or interface) body item.
`define ASSERT_IF(__name, __prop, __enable, __clk = `ASSERT_DEFAULT_CLK, __rst = `ASSERT_DEFAULT_RST) \
`ASSERT(__name, (__enable) |-> (__prop), __clk, __rst)
// Assert that signal has a known value (each bit is either '0' or '1') after reset if enable is
// set. It can be called as a module (or interface) body item.
`define ASSERT_KNOWN_IF(__name, __sig, __enable, __clk = `ASSERT_DEFAULT_CLK, __rst = `ASSERT_DEFAULT_RST) \
`ASSERT_KNOWN(__name``KnownEnable, __enable, __clk, __rst) \
`ASSERT_IF(__name, !$isunknown(__sig), __enable, __clk, __rst)
//////////////////////////////////
// For formal verification only //
//////////////////////////////////
// Note that the existing set of ASSERT macros specified above shall be used for FPV,
// thereby ensuring that the assertions are evaluated during DV simulations as well.
// ASSUME_FPV
// Assume a concurrent property during formal verification only.
`define ASSUME_FPV(__name, __prop, __clk = `ASSERT_DEFAULT_CLK, __rst = `ASSERT_DEFAULT_RST) \
`ifdef FPV_ON \
`ASSUME(__name, __prop, __clk, __rst) \
`endif
// ASSUME_I_FPV
// Assume a concurrent property during formal verification only.
`define ASSUME_I_FPV(__name, __prop) \
`ifdef FPV_ON \
`ASSUME_I(__name, __prop) \
`endif
// COVER_FPV
// Cover a concurrent property during formal verification
`define COVER_FPV(__name, __prop, __clk = `ASSERT_DEFAULT_CLK, __rst = `ASSERT_DEFAULT_RST) \
`ifdef FPV_ON \
`COVER(__name, __prop, __clk, __rst) \
`endif
// FPV assertion that proves that the FSM control flow is linear (no loops)
// The sequence triggers whenever the state changes and stores the current state as "initial_state".
// Then thereafter we must never see that state again until reset.
// It is possible for the reset to release ahead of the clock.
// Create a small "gray" window beyond the usual rst time to avoid
// checking.
`define ASSERT_FPV_LINEAR_FSM(__name, __state, __type, __clk = `ASSERT_DEFAULT_CLK, __rst = `ASSERT_DEFAULT_RST) \
`ifdef INC_ASSERT \
bit __name``_cond; \
always_ff @(posedge __clk or posedge __rst) begin \
if (__rst) begin \
__name``_cond <= 0; \
end else begin \
__name``_cond <= 1; \
end \
end \
property __name``_p; \
__type initial_state; \
(!$stable(__state) & __name``_cond, initial_state = $past(__state)) |-> \
(__state != initial_state) until (__rst == 1'b1); \
endproperty \
`ASSERT(__name, __name``_p, __clk, __rst) \
`endif
`include "prim_assert_sec_cm.svh"
`include "prim_flop_macros.sv"
`endif // PRIM_ASSERT_SV