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CLK/OSBindings/Mac/Clock SignalTests/C1540Tests.swift
2018-05-13 15:19:52 -04:00

74 lines
1.7 KiB
Swift

//
// C1540Tests.swift
// Clock Signal
//
// Created by Thomas Harte on 09/07/2016.
// Copyright 2016 Thomas Harte. All rights reserved.
//
import XCTest
class C1540Tests: XCTestCase {
fileprivate func with1540(_ action: (C1540Bridge) -> ()) {
let bridge = C1540Bridge()
action(bridge)
}
fileprivate func transmit(_ c1540: C1540Bridge, value: Int) {
var shiftedValue = value
c1540.dataLine = true
c1540.run(forCycles: 256)
XCTAssert(c1540.dataLine == false, "Listener should have taken data line low for start of transmission")
c1540.clockLine = true
c1540.run(forCycles: 256) // this isn't time limited on real hardware
XCTAssert(c1540.dataLine == true, "Listener should have let data line go high again")
// set up for byte transfer
c1540.clockLine = false
c1540.dataLine = true
c1540.run(forCycles: 40)
// transmit bits
for _ in 0..<8 {
// load data line
c1540.dataLine = (shiftedValue & 1) == 1
shiftedValue >>= 1
// toggle clock
c1540.clockLine = true
c1540.run(forCycles: 40)
c1540.clockLine = false
c1540.run(forCycles: 40)
}
// check for acknowledgment
c1540.dataLine = true
c1540.run(forCycles: 1000)
XCTAssert(c1540.dataLine == false, "Listener should have acknowledged byte")
}
// MARK: EOI
func testTransmission() {
with1540 {
// allow some booting time
$0.run(forCycles: 2000000)
// I want to be talker, so hold attention and clock low with data high
$0.clockLine = false
$0.attentionLine = false
$0.dataLine = true
// proceed 1 ms and check that the 1540 pulled the data line low
$0.run(forCycles: 1000)
XCTAssert($0.dataLine == false, "Listener should have taken data line low")
// transmit LISTEN #8
self.transmit($0, value: 0x28)
}
}
}