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110 lines
3.4 KiB
Swift
110 lines
3.4 KiB
Swift
//
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// Z80InterruptTests.swift
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// Clock Signal
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//
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// Created by Thomas Harte on 03/06/2017.
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// Copyright © 2017 Thomas Harte. All rights reserved.
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//
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import XCTest
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class Z80InterruptTests: XCTestCase {
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func testNMI() {
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let machine = CSTestMachineZ80()
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// start the PC at 0x0100 and install two NOPs for it
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machine.setValue(0x0100, for: .programCounter)
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machine.setValue(0, for: .IFF1)
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machine.setValue(1, for: .IFF2)
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machine.setValue(0x00, atAddress: 0x0100)
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machine.setValue(0x00, atAddress: 0x0101)
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// put the stack at the top of memory
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machine.setValue(0, for: .stackPointer)
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// run for four cycles, and signal an NMI
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machine.runForNumber(ofCycles: 4)
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machine.nmiLine = true
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// run for four more cycles to get to where the NMI should be recognised
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machine.runForNumber(ofCycles: 4)
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XCTAssertEqual(machine.value(for: .programCounter), 0x0102)
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// run for eleven more cycles to allow the NMI to begin
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machine.runForNumber(ofCycles: 11)
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// confirm that the PC is now at 0x66, that the old is on the stack and
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// that IFF1 has migrated to IFF2
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XCTAssertEqual(machine.value(for: .programCounter), 0x66)
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XCTAssertEqual(machine.value(atAddress: 0xffff), 0x01)
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XCTAssertEqual(machine.value(atAddress: 0xfffe), 0x02)
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XCTAssertEqual(machine.value(for: .IFF2), 0)
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}
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func testIRQDisabled() {
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let machine = CSTestMachineZ80()
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// start the PC at 0x0100, interrupts disabled
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machine.setValue(0x0100, for: .programCounter)
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machine.setValue(0, for: .IFF1)
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machine.setValue(0, for: .IFF2)
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// install six NOPs
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for address: UInt16 in 0x0100 ..< 0x0106 {
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machine.setValue(0x00, atAddress: address)
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}
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// replace the fourth NOP with an EI
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machine.setValue(0xfb, atAddress: 0x0103)
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// run for four cycles, signal IRQ and run for 8 more
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machine.runForNumber(ofCycles: 4)
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machine.irqLine = true
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machine.runForNumber(ofCycles: 8)
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// confirm that the request was ignored
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XCTAssertEqual(machine.value(for: .programCounter), 0x0103)
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// run for 12 more cycles, hitting the EI and, if no interrupt occured, the two NOPs after it
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machine.runForNumber(ofCycles: 12)
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// confirm that an interruption occurred, causing the PC not yet to have proceeded beyond 0x0105
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XCTAssertEqual(machine.value(for: .programCounter), 0x0105)
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}
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func testIRQMode1() {
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let machine = CSTestMachineZ80()
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// start the PC at 0x0100 and install three NOPs for it, ensuring interrupts are enabled
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// and in mode 1
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machine.setValue(0x0100, for: .programCounter)
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machine.setValue(1, for: .IFF1)
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machine.setValue(1, for: .IM)
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machine.setValue(0x00, atAddress: 0x0100)
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machine.setValue(0x00, atAddress: 0x0101)
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machine.setValue(0x00, atAddress: 0x0102)
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// put the stack at the top of memory
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machine.setValue(0, for: .stackPointer)
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// run for four cycles, and signal an IRQ
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machine.runForNumber(ofCycles: 4)
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machine.irqLine = true
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// run for four more cycles to get to where the IRQ should be recognised
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machine.runForNumber(ofCycles: 4)
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XCTAssertEqual(machine.value(for: .programCounter), 0x0102)
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// run for eleven more cycles to allow the IRQ to begin
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machine.runForNumber(ofCycles: 13)
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// confirm that the PC is now at 0x38, that the old is on the stack and
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// that interrupts are now disabled
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XCTAssertEqual(machine.value(for: .programCounter), 0x38)
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XCTAssertEqual(machine.value(atAddress: 0xffff), 0x01)
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XCTAssertEqual(machine.value(atAddress: 0xfffe), 0x02)
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XCTAssertEqual(machine.value(for: .IFF1), 0)
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}
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}
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