APB VIP Integration Guide

1. Instantiate the interface

apb_if always contains APB4 signals (PPROT, PSTRB) so that a single compiled image can run in APB3 or APB4 mode.

Example:

localparam int ADDR_W = 16;
localparam int DATA_W = 32;
localparam int NSEL   = 1;

logic PCLK, PRESETn;
apb_if #(ADDR_W, DATA_W, NSEL) apb (.*);

2. Connect virtual interface

uvm_config_db#(virtual apb_if #(ADDR_W, DATA_W, NSEL))::set(null, "*", "vif", apb);

3. Create master/slave agents

Use apb_env_cfg + apb_agent_cfg:

• One agent configured as master (active)
• One agent configured as slave (active) with a simple memory model

See the example implementation in kvips/apb/examples/uvm_back2back/tb/tb_pkg.sv.

4. Select APB3 vs APB4 (runtime)

• APB4 (default): +APB_PROTOCOL=APB4
• APB3: +APB_PROTOCOL=APB3

Notes:

• APB3 mode forces PPROT=0 and PSTRB='1 in the master driver.
• APB4-only assertions are disabled when +APB_PROTOCOL=APB3.

5. Scoreboard and validation

The example connects:

• apb_monitor → analysis port
• apb_scoreboard → checks read data against expected memory updates

Disable scoreboard via:

• +KVIPS_APB_SB_OFF or uvm_config_db#(bit)::set(this, "sb", "enable", 1'b0)

6. Transaction recording (optional)

Enable transaction recording via:

• +VIP_TR (example TB maps this to cfg.tr_record_enable)

7. Debug switches

Common plusargs in the example TB:

• +VIP_TRACE – enable concise per-transaction prints
• +VIP_COV – enable monitor functional coverage sampling
• +VIP_TR – enable transaction recording

Assertions:

• +KVIPS_APB_ASSERT_OFF – disable all APB assertions
• +KVIPS_APB_ASSERT_KNOWN_OFF – disable X/known-value checks
• +KVIPS_APB_ASSERT_STRICT_OFF – disable strict rules (e.g. strobe nonzero)