1CADENCE DESIGN SYSTEMS, INC. Cadence Proposed Transaction Level Interface Enhancements for SCE-MI SEPTEMBER 11, 2003

2 Agenda End-user goals Transaction level requirements Proposed SCE-MI enhancements

3 End-User Goal: Verification Performance Verify Large, Complex systems efficiently –Hardware assisted boosts verification performance for –large sub-systems –long-run tests (e.g. regression suite) –Transaction-based Interfaces improve performance by –infrequent transactions that reduces communications between hardware and software –allowing message level communication with smart transactors that interpret these messages in the HW

4 But Software Simulation is still Required Using abstract verification and design components –Rich functional capability –Comprehensive debug capabilities Acceleration Hardware is usually less efficient –at small sub-system verification –with interactive debug sessions Conclusion – Users are expected to start with SW simulation before moving to accelerated simulation. –Verification reuse from block/ sub-system to system is important –Maintaining congruent configurations using the same testbench is important

5 SW-based Verification Flow Componentized SW based design and verification flow contains –Abstracted Testbench – Transaction level tests and response checkers –Abstracted DUT – Abstracted Transaction Level Model (TLM) –DUT – RTL model of the Device Under Test –Transactors – Bus functional models that refine communication between abstracted testbench and DUT Abstracted Testbench Abstracted DUT (TLM) Abstracted Testbench Transactors DUT (HDL) Phase 1 (High Level Design) Phase 2 (SW-based Verification)

6 Accelerated Verification Flow Abstracted Testbench Accel DUT (HDL) Phase 3 (HW-assisted Verification) Transport C/ C++ HDL Abstracted Testbench Abstracted DUT Phase 1 (High Level Design) Abstracted Testbench Transactors (Mix C/C++/HDL) DUT (HDL) Phase 2 (SW-based Verification)

7 End-user Goal: Reusability Abstracted Testbench Abstracted DUT Abstracted Testbench Transactors (Mix C/C++/HDL) DUT (HDL) Phase 1 (High Level Design) Phase 2 (SW-based Verification) Abstracted Testbench Accel DUT (HDL) Phase 3 (HW-assisted Verification) Transport C/ C++ HDL

8 Reusability can be accomplished by Common Transaction Level Interface (TLI) that enables reuse –Same exposable TLI interfaces in SW-based and HW-assisted verification –Reusable abstracted testbench components and transactors –Congruent configurations in SW-based simulation and Emulation/Acceleration –Allows the user to switch among verification engines seamlessly Abstracted Testbench DUT (HDL) Phase 2 (SW-based Verification) Abstracted Testbench Accel DUT (HDL) Phase 3 (HW-assisted Verification) TLI C/ C++ HDL C/ C++ HDL TLI

9 Transaction Level Requirements Transaction definition –Generic, arbitrarily-sized hierarchical transaction payload Common transaction-level interface definition –Basic input/output transaction interface –Signal-level definition for HDL part of the transactors –Corresponding C/C++ interface for the abstracted part of the transactors communicating with the corresponding HDL part TLI must be independent of verification engine technology. –The HDL part of the transactors can be implemented using a simple FSM –The abstracted part of the transactors can use any HLL that can interface with a simple C/C++ API

10 SCE-MI 1.0 Key Drawbacks Variable-Length Transaction handling must be (re-)coded for all ‘hardware side’ components Precludes transactor re-use between event-based and cycle-based engines by –exposing ‘uncontrolled clock’ to end-user –assuming underlying cycle-based emulation/simulation technology Abstracted Testbench DUT (HDL) Phase 2 SW (event-based) TLI C/ C++ HDL TLI Abstracted Testbench Accel DUT (HDL) Phase 3 Accel (TLI) C/ C++ HDL Abstracted Testbench Accel DUT (HDL) Phase 3 Accel (SCE-MI) C/ C++ HDL SCE-MI 1.0

11 TLI Proposal will provide a complete Transaction-Level Interface for robust, variable length transaction processing decouple the HDL API from the underlying cycle-based simulation/emulation system architecture –Remove the uncontrolled clock mechanism from the public interface of the API provide a low-level engine independent transactional transport API in C/C++ –Facilitates transaction-level integration of emulation with diverse high level software engines (Pure C/C++, SystemC, System Verilog, PLi, etc.) C/C++ HDL TLI Transactor HLL Signals