CocoTB Framework · Verification Infrastructure for RTL Testing
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IRQ Components¶

Passive observation for plain interrupt lines — level or pulse, scalar or vector. An interrupt wire has no handshake, so it gets its own monitor instead of riding the GAXI machinery: sample on a clock edge, decompose the transition into one packet per changed bit, and answer the questions interrupt tests actually ask ("did this line assert, when, and did anything ELSE move?").

Component Overview¶

Component	Purpose
IRQMonitor	Passive monitor for ONE interrupt line, scalar or vector. Samples on a clock edge and emits one `IRQPacket` per changed bit.
IRQMonitorGroup	Several lines watched as one unit, from ONE sampling coroutine, with set-based assertions (`expect_only`) for the negative case.
IRQPacket	One observed transition on one line — time, per-bit index, whole-vector value.

Pages¶

IRQ Components Overview — when to use this family, when NOT to, and the design decisions behind it
IRQMonitor — per-line monitor API
IRQMonitorGroup — group API, single-coroutine sampling, expect_only
IRQPacket — the transition packet

Quick Start¶

from CocoTBFramework.components.irq import IRQMonitorGroup

irqs = IRQMonitorGroup(dut, dut.pclk, {
    'gpio_irq':      None,     # width auto-detected
    'pic_int_out':   None,
    'pit_timer_irq': None,     # vector: one event per bit
    'rlb_irq_out':   None,
}, title="RLB")
irqs.start()
# ... run the stimulus ...
ok, missing, unexpected = irqs.expect_only(['gpio_irq', 'pic_int_out',
                                            'rlb_irq_out'])
irqs.stop()

A line named in the map that does not exist on the DUT is skipped with a warning, so the same map can serve several DUT variants.

The One Rule¶

A line with a handshake is not an interrupt line. The moment a delivery channel grows valid/ready/retry — the IOAPIC's irq_out_valid / irq_out_ready / irq_out_retry, for instance — it belongs to GAXI, not here. This family is only for wires where assertion IS the event.