Merge pull request #1 from c-thaler/apb_vc

Apb vc

docs/verification_components/user_guide.rst

@@ -90,3 +90,115 @@ A VC typically has an associated package defining procedures for sending to and
 Each VC instance is associated with a handle that is created in the test bench and set as a generic on the VC
 instantiation.
 The handle is given as an argument to the procedure calls to direct messages to the specific VC instance.
+
+
+VC and VCI Compliance Testing
+=============================
+
+VUnit establishes a standard for VCs and VCIs, designed around a set of rules that promote flexibility,
+reusability, interoperability, and future-proofing of VCs and VCIs.
+
+Rule 1
+------
+
+The file containing the VC entity shall contain only that entity, and the file containing the VCI package shall
+contain only that package.
+
+**Rationale**: This structure simplifies compliance testing, as each VC or VCI can be directly referenced by its
+file name.
+
+Rule 2
+------
+
+A VC shall have only **one** generic, the *handle*, and it shall be of a record type containing **private** fields.
+
+**Rationale**: Using a record allows future updates to add and/or remove fields in the record without breaking
+backward compatibility.
+
+**Recommendation**: Mark the fields as private by using a naming convention and/or including comments. This minimizes
+the risk of users accessing fields directly.
+
+Rule 3
+------
+
+The VC handle shall be created by a function, the *constructor*, which shall have a name beginning with ``new``.
+
+**Rationale**: Using a constructor removes the need for users to directly access the private fields of the handle
+record. The naming convention also enables compliance tests to easily locate the constructor and verify it against
+other applicable rules.
+
+Rule 4
+------
+
+The VC constructor shall include an ``id`` parameter of type ``id_t`` to enable the user to specify the VC's identity.
+
+**Rationale**: This gives users control over the namespace assigned to the VC.
+
+Rule 5
+------
+
+The ``id`` parameter shall default to ``null_id``. If not overridden, ``id`` shall be assigned a value on the format
+``<provider>:<VC name>:<n>``, where ``<n>`` starts at 1 for the first instance of the VC and increments with each
+additional instance.
+
+**Rationale**: This format ensures clear identification while preventing naming collisions when VCs from different
+providers are combined.
+
+Rule 6
+------
+
+All identity-supporting objects associated with the VC (such as loggers, actors, and events) shall be assigned an
+identity within the namespace defined by the constructor’s ``id`` parameter.
+
+**Rationale**: This gives users control over these objects and simplifies the association of log messages with a
+specific VC instance.
+
+Rule 7
+------
+
+All logging performed by the VC, including indirect logging (such that error logs from checkers), shall use the
+VUnit logging mechanism.
+
+**Rationale**: Using a unified logging mechanism ensures consistency and compatibility across logging outputs
+from different VCs.
+
+Rule 8
+------
+
+Communication with the VC shall be based on VUnit message passing, and the VC actor’s identity shall match the
+``id`` parameter provided to the constructor.
+
+**Rationale**: This ensures a consistent communication framework and enables the reuse of VCIs across multiple VCs.
+
+Rule 9
+------
+
+All VCs shall support the sync interface.
+
+**Rationale**: The ability to verify if a VC is idle and to introduce delays between transactions are frequently
+needed features for VC users.
+
+Rule 10
+-------
+
+The VC constructor shall include an ``unexpected_msg_type_policy`` parameter, allowing users to specify the action
+taken when the VC receives an unexpected message type.
+
+**Rationale**: This policy enables flexibility in handling situations where a VC actor, subscribed to another actor,
+might receive unsupported messages, while VCs addressed directly should only receive supported messages.
+
+Rule 11
+-------
+
+The standard configuration (of type ``std_cfg_t``), which includes the required parameters for the constructor, shall
+be accessible by calling ``get_std_cfg`` with the VC handle.
+
+**Rationale**: This enables reuse of common functions across multiple VCs.
+
+Rule 12
+-------
+
+A VC shall keep the ``test_runner_cleanup`` phase entry gate locked as long as there are pending operations.
+
+**Rationale**: Locking the gate ensures that the simulation does not terminate prematurely before all operations have
+completed.

vunit/vhdl/verification_components/src/apb_completer.vhd

@@ -0,0 +1,84 @@
+-- This Source Code Form is subject to the terms of the Mozilla Public
+-- License, v. 2.0. If a copy of the MPL was not distributed with this file,
+-- You can obtain one at http://mozilla.org/MPL/2.0/.
+--
+-- Copyright (c) 2014-2024, Lars Asplund [email protected]
+
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+
+library osvvm;
+use osvvm.RandomPkg.RandomPType;
+
+use work.memory_pkg.all;
+use work.apb_completer_pkg.all;
+use work.logger_pkg.all;
+
+entity apb_completer is
+  generic (
+    bus_handle        : apb_completer_t
+  );
+  port (
+    clk                 : in  std_logic;
+    reset               : in  std_logic;
+    psel_i              : in  std_logic;
+    penable_i           : in  std_logic;
+    paddr_i             : in  std_logic_vector;
+    pwrite_i            : in  std_logic;
+    pwdata_i            : in  std_logic_vector;
+    prdata_o            : out std_logic_vector;
+    pready_o            : out std_logic
+  );
+end entity;
+
+architecture a of apb_completer is
+
+begin
+
+  PROC_MAIN: process
+    procedure drive_outputs_invalid is
+    begin
+      if bus_handle.p_drive_invalid then
+        prdata_o <= (prdata_o'range => bus_handle.p_drive_invalid_val);
+        pready_o <= bus_handle.p_drive_invalid_val;
+      end if;
+    end procedure;
+
+    variable addr : integer;
+    variable rnd : RandomPType;
+  begin
+    drive_outputs_invalid;
+    wait until rising_edge(clk);
+
+    loop
+      -- IDLE/SETUP state
+      drive_outputs_invalid;
+
+      wait until psel_i = '1' and rising_edge(clk);
+      -- ACCESS state
+
+      while rnd.Uniform(0.0, 1.0) > bus_handle.p_ready_high_probability loop
+        pready_o <= '0';
+        wait until rising_edge(clk);
+      end loop;
+
+      pready_o <= '1';
+
+      addr := to_integer(unsigned(paddr_i));
+
+      if pwrite_i = '1' then
+        write_word(bus_handle.p_memory, addr, pwdata_i);
+      else
+        prdata_o <= read_word(bus_handle.p_memory, addr, prdata_o'length/8);
+      end if;
+
+      wait until rising_edge(clk);
+
+      if penable_i = '0' then
+        failure(bus_handle.p_logger, "penable_i must be active in the ACCESS phase.");
+      end if;
+    end loop;
+  end process;
+
+end architecture;

vunit/vhdl/verification_components/src/apb_completer_pkg.vhd

@@ -0,0 +1,76 @@
+-- This Source Code Form is subject to the terms of the Mozilla Public
+-- License, v. 2.0. If a copy of the MPL was not distributed with this file,
+-- You can obtain one at http://mozilla.org/MPL/2.0/.
+--
+-- Copyright (c) 2014-2024, Lars Asplund [email protected]
+
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+
+use work.bus_master_pkg.all;
+use work.com_pkg.all;
+use work.com_types_pkg.all;
+use work.logger_pkg.all;
+use work.memory_pkg.memory_t;
+use work.memory_pkg.to_vc_interface;
+
+package apb_completer_pkg is
+
+  type apb_completer_t is record
+    -- Private
+    p_actor : actor_t;
+    p_memory : memory_t;
+    p_logger : logger_t;
+    p_drive_invalid     : boolean;
+    p_drive_invalid_val : std_logic;
+    p_ready_high_probability : real range 0.0 to 1.0;
+  end record;
+
+  constant apb_completer_logger : logger_t := get_logger("vunit_lib:apb_completer_pkg");
+  impure function new_apb_completer(
+    memory : memory_t;
+    logger : logger_t := null_logger;
+    actor : actor_t := null_actor;
+    drive_invalid : boolean := true;
+    drive_invalid_val : std_logic := 'X';
+    ready_high_probability : real := 1.0)
+    return apb_completer_t;
+
+    constant slave_write_msg  : msg_type_t := new_msg_type("apb slave write");
+    constant slave_read_msg   : msg_type_t := new_msg_type("apb slave read");
+end package;
+
+package body apb_completer_pkg is
+
+  impure function new_apb_completer(
+    memory : memory_t;
+    logger : logger_t := null_logger;
+    actor : actor_t := null_actor;
+    drive_invalid : boolean := true;
+    drive_invalid_val : std_logic := 'X';
+    ready_high_probability : real := 1.0)
+    return apb_completer_t is
+    variable actor_tmp : actor_t := null_actor;
+    variable logger_tmp : logger_t := null_logger;
+  begin
+    if actor = null_actor then
+      actor_tmp := new_actor;
+    else
+      actor_tmp := actor;
+    end if;
+    if logger = null_logger then
+      logger_tmp := bus_logger;
+    else
+      logger_tmp := logger;
+    end if;
+    return (
+      p_memory => to_vc_interface(memory, logger),
+      p_logger => logger_tmp,
+      p_actor => actor_tmp,
+      p_drive_invalid => drive_invalid,
+      p_drive_invalid_val => drive_invalid_val,
+      p_ready_high_probability => ready_high_probability
+    );
+  end;
+end package body;