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CLK/OSBindings/Mac/Clock SignalTests/6502InterruptTests.swift
2018-05-13 15:19:52 -04:00

76 lines
2.6 KiB
Swift

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