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CLK/OSBindings/Mac/Clock SignalTests/6522Tests.swift
2016-11-05 12:58:56 -04:00

129 lines
4.3 KiB
Swift

//
// 6522Tests.swift
// Clock Signal
//
// Created by Thomas Harte on 18/06/2016.
// Copyright © 2016 Thomas Harte. All rights reserved.
//
import XCTest
import Foundation
class MOS6522Tests: XCTestCase {
fileprivate func with6522(_ action: (MOS6522Bridge) -> ()) {
let bridge = MOS6522Bridge()
action(bridge)
}
// MARK: Timer tests
func testTimerCount() {
with6522 {
// set timer 1 to a value of $000a
$0.setValue(10, forRegister: 4)
$0.setValue(0, forRegister: 5)
// complete the setting cycle
$0.run(forHalfCycles: 2)
// run for 5 cycles
$0.run(forHalfCycles: 10)
// check that the timer has gone down by 5
XCTAssert($0.value(forRegister: 4) == 5, "Low order byte should be 5; was \($0.value(forRegister: 4))")
XCTAssert($0.value(forRegister: 5) == 0, "High order byte should be 0; was \($0.value(forRegister: 5))")
}
}
func testTimerLatches() {
with6522 {
// set timer 2 to $1020
$0.setValue(0x10, forRegister: 8)
$0.setValue(0x20, forRegister: 9)
// change the low-byte latch
$0.setValue(0x40, forRegister: 8)
// complete the cycle
$0.run(forHalfCycles: 2)
// chek that the new latched value hasn't been copied
XCTAssert($0.value(forRegister: 8) == 0x10, "Low order byte should be 0x10; was \($0.value(forRegister: 8))")
XCTAssert($0.value(forRegister: 9) == 0x20, "High order byte should be 0x20; was \($0.value(forRegister: 9))")
// write the low-byte latch
$0.setValue(0x50, forRegister: 9)
// complete the cycle
$0.run(forHalfCycles: 2)
// chek that the latched value has been copied
XCTAssert($0.value(forRegister: 8) == 0x40, "Low order byte should be 0x50; was \($0.value(forRegister: 8))")
XCTAssert($0.value(forRegister: 9) == 0x50, "High order byte should be 0x40; was \($0.value(forRegister: 9))")
}
}
func testTimerReload() {
with6522 {
// set timer 1 to a value of $0010, enable repeating mode
$0.setValue(16, forRegister: 4)
$0.setValue(0, forRegister: 5)
$0.setValue(0x40, forRegister: 11)
$0.setValue(0x40 | 0x80, forRegister: 14)
// complete the cycle to set initial values
$0.run(forHalfCycles: 2)
// run for 16 cycles
$0.run(forHalfCycles: 32)
// check that the timer has gone down to 0 but not yet triggered an interrupt
XCTAssert($0.value(forRegister: 4) == 0, "Low order byte should be 0; was \($0.value(forRegister: 4))")
XCTAssert($0.value(forRegister: 5) == 0, "High order byte should be 0; was \($0.value(forRegister: 5))")
XCTAssert(!$0.irqLine, "IRQ should not yet be active")
// check that two half-cycles later the timer is $ffff but IRQ still hasn't triggered
$0.run(forHalfCycles: 2)
XCTAssert($0.value(forRegister: 4) == 0xff, "Low order byte should be 0xff; was \($0.value(forRegister: 4))")
XCTAssert($0.value(forRegister: 5) == 0xff, "High order byte should be 0xff; was \($0.value(forRegister: 5))")
XCTAssert(!$0.irqLine, "IRQ should not yet be active")
// check that one half-cycle later the timer is still $ffff and IRQ has triggered...
$0.run(forHalfCycles: 1)
XCTAssert($0.irqLine, "IRQ should be active")
XCTAssert($0.value(forRegister: 4) == 0xff, "Low order byte should be 0xff; was \($0.value(forRegister: 4))")
XCTAssert($0.value(forRegister: 5) == 0xff, "High order byte should be 0xff; was \($0.value(forRegister: 5))")
// ... but that reading the timer cleared the interrupt
XCTAssert(!$0.irqLine, "IRQ should be active")
// check that one half-cycles later the timer has reloaded
$0.run(forHalfCycles: 1)
XCTAssert($0.value(forRegister: 4) == 0x10, "Low order byte should be 0x10; was \($0.value(forRegister: 4))")
XCTAssert($0.value(forRegister: 5) == 0x00, "High order byte should be 0x00; was \($0.value(forRegister: 5))")
}
}
// MARK: Data direction tests
func testDataDirection() {
with6522 {
// set low four bits of register B as output, the top four as input
$0.setValue(0xf0, forRegister: 2)
// ask to output 0x8c
$0.setValue(0x8c, forRegister: 0)
// complete the cycle
$0.run(forHalfCycles: 2)
// set current input as 0xda
$0.portBInput = 0xda
// test that the result of reading register B is therefore 0x8a
XCTAssert($0.value(forRegister: 0) == 0x8a, "Data direction register should mix input and output; got \($0.value(forRegister: 0))")
}
}
}