title: “PADCTRL DV Plan”

Goals

  • DV:

    • PADCTRL is decided to verify in FPV only

  • FPV:

    • Verify all the PADCTRL 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.md” >}})
  • FPV dashboard (link TBD)

Design features

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

Testbench architecture

PADCTRL FPV testbench has been constructed based on the [formal architecture]({{< relref “hw/formal/README.md” >}}). The PADCTRL testbench consists of two RTL modules: padctrl and padring.

Block diagram

Block diagram

TLUL assertions

  • The ../fpv/tb/padctrl_bind.sv binds the tlul_assert [assertions]({{< relref “hw/ip/tlul/doc/TlulProtocolChecker.md” >}}) with padctrl to ensure TileLink interface protocol compliance
  • TODO: Plan to implement csr assertions under ../fpv/vip/ to assert the TileLink writes and reads correct CSRs

PADCTRL assertions

  • The ../fpv/tb/padctrl_bind_fpv.sv binds module padctrl_assert_fpv with the padctrl RTL. The assertion file ensures padctrl's outputs (mio_attr_o and dio_attr_o) under the generic or Xilinx implementation are verified.
  • The ../fpv/tb/padctrl_bind_fpv.sv also binds module padring_assert_fpv with the padring RTL. The assertion file ensures all the padring's outputs are verified.
Symbolic variables

Due to there are large number of muxed and dedicated IOs, the symbolic variable is used to reduce the number of repeated assertions code. In padctrl_assert_fpv and padring_assert_fpv, we declared two symbolic variables mio_sel and dio_sel to represent the index for muxed IO and dedicated IO. Detailed explanation is listed in the [Symbolic Variables]({{< relref “hw/formal/README.md#symbolic-variables” >}}) section.

Testplan

{{< testplan “hw/ip/padctrl/data/padctrl_fpv_testplan.hjson” >}}