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76 lines
2.6 KiB
Swift
76 lines
2.6 KiB
Swift
//
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// 6502InterruptTests.swift
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// Clock Signal
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//
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// Created by Thomas Harte on 28/06/2016.
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// Copyright © 2016 Thomas Harte. All rights reserved.
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//
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import XCTest
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class MOS6502InterruptTests: XCTestCase {
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var machine: CSTestMachine6502! = nil
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override func setUp() {
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super.setUp()
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// create a machine full of NOPs
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machine = CSTestMachine6502()
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for c in 0...65535 {
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machine.setValue(0xea, forAddress: UInt16(c))
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}
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// set the IRQ vector to be 0x1234
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machine.setValue(0x34, forAddress: 0xfffe)
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machine.setValue(0x12, forAddress: 0xffff)
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// add a CLI
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machine.setValue(0x58, forAddress: 0x4000)
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// pick things off at 0x4000
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machine.setValue(0x4000, for: CSTestMachine6502Register.programCounter)
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}
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func testIRQLine() {
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// run for six cycles; check that no interrupt has occurred
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machine.runForNumber(ofCycles: 6)
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XCTAssert(machine.value(for: .programCounter) == 0x4003, "No interrupt should have occurred with line low")
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// enable the interrupt line, check that it was too late
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machine.irqLine = true
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machine.runForNumber(ofCycles: 2)
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XCTAssert(machine.value(for: .programCounter) == 0x4004, "No interrupt should have occurred from interrupt raised between instructions")
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// run for a further 7 cycles, confirm that the IRQ vector was jumped to
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machine.runForNumber(ofCycles: 6)
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XCTAssert(machine.value(for: .programCounter) != 0x1234, "Interrupt routine should not yet have begun")
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machine.runForNumber(ofCycles: 1)
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XCTAssert(machine.value(for: .programCounter) == 0x1234, "Interrupt routine should just have begun")
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}
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func testIFlagSet() {
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// enable the interrupt line, run for eleven cycles to get past the CLIP and the following NOP and into the interrupt routine
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machine.irqLine = true
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machine.runForNumber(ofCycles: 11)
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XCTAssert(machine.value(for: .programCounter) == 0x1234, "Interrupt routine should just have begun")
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XCTAssert(machine.value(for: .flags) & 0x04 == 0x04, "Interrupt status flag should be set")
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}
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func testCLISEIFlagClear() {
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// set up an SEI as the second instruction, enable the IRQ line
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machine.setValue(0x78, forAddress: 0x4001)
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machine.irqLine = true
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// run for four cycles; the CLI and SEI should have been performed
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machine.runForNumber(ofCycles: 4)
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XCTAssert(machine.value(for: .programCounter) == 0x4002, "CLI/SEI pair should have been performed in their entirety")
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// run for seven more cycles
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machine.runForNumber(ofCycles: 7)
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// interrupt should have taken place despite SEI
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XCTAssert(machine.value(for: .programCounter) == 0x1234, "Interrupt routine should just have begun")
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}
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}
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