irq.c

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/*
 
MIT License
 
Copyright (c) 2026 PCSX-Redux authors
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
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The above copyright notice and this permission notice shall be included in all
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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SOFTWARE.
 
*/
 
// GP0(1Fh)/GP1(02h) IRQ flag behavior. See gpu-irq.c for the bit map.
 
// clang-format off
 
CESTER_BODY(
 
// Request IRQ1 via GP0(1Fh) and let the GPU consume it before the read.
static void gpuIrqRequest(void) {
    waitGPU();
    GPU_DATA = 0x1f000000u;
    waitGPU();
}
 
// Acknowledge IRQ1 via GP1(02h). GP1 is a control-port command; give the
// status bit a moment to settle before it is read back.
static void gpuIrqAck(void) {
    sendGPUStatus(0x02000000u);
    for (volatile int i = 0; i < 64; i++) {
        (void)GPU_STATUS;
    }
}
 
)  // CESTER_BODY
 
// --------------------------------------------------------------------------
// 1. The IRQ flag is clear after a full reset.
// --------------------------------------------------------------------------
CESTER_TEST(irq_clear_after_reset, gpu_irq,
    rasterReset();
    gpuIrqRequest();  // raise it, so the reset has something to clear
    ASSERT_STAT_EQ(GPUSTAT_IRQ, GPUSTAT_IRQ);
    rasterReset();  // includes GP1(00h) full reset
    ASSERT_STAT_EQ(0u, GPUSTAT_IRQ);
)
 
// --------------------------------------------------------------------------
// 2. GP0(1Fh) sets GPUSTAT.24.
// --------------------------------------------------------------------------
CESTER_TEST(irq_gp0_1f_sets_flag, gpu_irq,
    rasterReset();
    gpuIrqRequest();
    ASSERT_STAT_EQ(GPUSTAT_IRQ, GPUSTAT_IRQ);
)
 
// --------------------------------------------------------------------------
// 3. GP1(02h) acknowledges and clears a raised IRQ flag.
// --------------------------------------------------------------------------
CESTER_TEST(irq_gp1_02_acknowledges, gpu_irq,
    rasterReset();
    gpuIrqRequest();          // raise it
    ASSERT_STAT_EQ(GPUSTAT_IRQ, GPUSTAT_IRQ);
    gpuIrqAck();              // GP1(02h)
    ASSERT_STAT_EQ(0u, GPUSTAT_IRQ);
)