title: “RV_PLIC dv document”

Goals

  • DV:

    • RV_PLIC is decided to verify in FPV only

  • FPV:

    • Verify all the RV_PLIC outputs by writing assumptions and assertions with a FPV based testbench
    • Verify TileLink device protocol compliance with a FPV based testbench

Current status

  • [Design & verification stage]({{< relref “hw” >}})
    • [HW development stages]({{< relref “doc/project/development_stages” >}})
  • FPV dashboard (link TBD)

Design features

For detailed information on RV_PLIC design features, please see the [RV_PLIC design specification]({{< relref “hw/ip/rv_plic/doc” >}}).

Testbench architecture

RV_PLIC FPV testbench has been constructed based on the [formal architecture]({{< relref “hw/formal/README.md” >}}).

Block diagram

Block diagram

TLUL assertions

  • The hw/rv_plic/fpv/tb/rv_plic_bind.sv binds the tlul_assert [assertions]({{< relref “hw/ip/tlul/doc/TlulProtocolChecker.md” >}}) to rv_plic to ensure TileLink interface protocol compliance.
  • The hw/rv_plic/fpv/tb/rv_plic_bind.sv also binds the rv_plic_csr_assert_fpv under hw/rv_plic/fpv/vip/ to check if TileLink writes and reads correct CSRs.

RV_PLIC assertions

The hw/rv_plic/fpv/tb/rv_plic_bind.sv binds the rv_plic_assert under hw/rv_plic/fpv/vip/rv_plic_assert.sv. The assertion file ensures RV_PLIC's outputs (irq_o and irq_id_o) and important signals (ip) are being asserted.

Symbolic variables

Due to there are large number of input interrupt sources, the symbolic variable is used to reduce the number of repeated assertions code. In RV_PLIC, we declared two symbolic variables src_sel and tgt_sel to represent the index for interrupt source and interrupt target. Detailed explanation is listed in the [Symbolic Variables]({{< relref “hw/formal/README.md#symbolic-variables” >}}) section.

Testplan

{{< testplan “hw/ip/rv_plic/data/rv_plic_fpv_testplan.hjson” >}}