Verify

Verification Framework for buckyball

Environment

This repository uses Nix and the UVM version is 1.2. We default there is VCS in the local EDA environment.

Enter the environment:

nix develop

The dev shell exports:

UVM_HOME
UVM_VERSION
VCS_UVM_ARGS

It also provides the Rust toolchain used by Ball-local DPI reference models:

cargo
rustc
rustfmt
clippy

VCS_UVM_ARGS expands to the UVM 1.2 compile inputs needed by VCS:

+incdir+$UVM_HOME/src $UVM_HOME/src/uvm.sv $UVM_HOME/src/dpi/uvm_dpi.cc -CFLAGS -DVCS

Common UVM

Reusable Ball-level UVM pieces live under uvm/src/ball/:

uvm/src/ball/bb_uvm_pkg.sv
uvm/src/ball/bb_blink_defs.svh
uvm/src/ball/bb_blink_items.svh
uvm/src/ball/bb_blink_if.sv
uvm/src/ball/agents/cmd/bb_blink_cmd_driver.svh
uvm/src/ball/agents/cmd/bb_blink_cmd_monitor.svh
uvm/src/ball/agents/cmd/bb_blink_cmd_agent.svh
uvm/src/ball/agents/mem/bb_blink_mem_model.svh
uvm/src/ball/agents/mem/bb_blink_mem_monitor.svh
uvm/src/ball/agents/resp/bb_blink_resp_monitor.svh
uvm/src/ball/cov/bb_blink_cov.svh
uvm/src/ball/env/bb_blink_env.svh

Ball verify filelists should compile bb_blink_if.sv and bb_uvm_pkg.sv before the Ball-specific package. Ball filelists use @UVM@ and @RTL@ placeholders for the common UVM tree and the Ball RTL build output, respectively. The common package provides Blink transaction items, the command agent, the bank read/write memory model and monitors, the command response monitor, the protocol coverage collector, and the bb_blink_env base environment.

+incdir notes

When compiling bb_uvm_pkg.sv, the following +incdir+ entries are required so that the nested agents/... includes resolve:

+incdir+uvm/src/ball
+incdir+uvm/src/ball/agents/cmd
+incdir+uvm/src/ball/agents/mem
+incdir+uvm/src/ball/agents/resp
+incdir+uvm/src/ball/cov
+incdir+uvm/src/ball/env

bb_uvm_pkg.sv includes files in dependency order:

defs -> items -> cmd driver -> cmd monitor -> cmd agent
      -> mem model -> mem monitor -> resp monitor -> cov -> env

Ownership: framework vs ball

• Framework-owned (uvm/src/ball/): the shared Ball/Blink framework. The Blink transaction items, the bb_blink_if interface, the command agent (driver + monitor + agent), the bank read/write memory model and monitors, the response monitor, the protocol coverage collector (bb_blink_cov), and the base bb_blink_env. These are shared by every Ball and must not be edited by a Ball-local testbench.
• Ball-owned (Ball verify tree, e.g. examples/balls/<ball>/verify/ in the Buckyball monorepo): the Ball-specific package, sequences, the Ball scoreboard, the Ball env subclass that extends bb_blink_env and adds the scoreboard + analysis connections, the test, and the filelist. A Ball extends bb_blink_env#(IN,OUT) and wires its scoreboard into the agent/monitor analysis ports exposed by the base env.

The base bb_blink_env constructs only the protocol-level pieces (cmd agent, mem model, read/write/resp monitors, cov) and connects monitor APs to the coverage collector. It deliberately leaves scoreboard construction and any end-to-end checking to the Ball subclass.

Generic IP-level components live under uvm/src/ip/. They operate on UVM transaction types and do not contain DUT interfaces, port names, or IP lists. They provide the reference-model connection, ordered result checking, explicit cancellation of pending expectations on reset, and a test base with a timeout. Tests wait for the required number of checked results before completing.

Reusable AXI4-Stream interfaces, items, source agents, monitors, backpressure control, assertions, and protocol coverage live under uvm/src/protocol/axis/. They parameterize the data width and currently carry TDATA, TKEEP, and TLAST. Reset during an active source transfer is reported as a failure. Each IP owns its DUT wiring, protocol-specific extensions, reference-model binding, environment composition, and test scenarios in its source tree. An IP filelist can have a matching .el file with annotated, instance-scoped coverage exclusions. bbdev retains the full report and writes rtl_raw/ and rtl/ reports for the DUT before and after exclusions. Exclusion checksums must match the current database; mismatches require review and fail reporting.