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Fixed lost 8080 interrupts, and added new CPU-driven setTimer() functionality

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This commit is contained in:
Jeff Parsons 2016-08-17 11:58:01 -07:00
commit 99023617fd
6 changed files with 562 additions and 447 deletions
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38
modules/pc8080/lib/serialport.js
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@ -115,15 +115,6 @@ function SerialPort(parmsSerial) {
Component.bindExternalControl(this, sBinding, SerialPort.sIOBuffer);
}
/*
* Define a setTimeout() function that receiveData() can use when there's more data to receive.
*/
this.fnCheckDataReceived = function(serial) {
return function() {
serial.receiveData();
}
}(this);
/*
* No connection until initBus() invokes initConnection().
*/
@ -368,10 +359,20 @@ SerialPort.prototype.initBus = function(cmp, bus, cpu, dbg)
this.bus = bus;
this.cpu = cpu;
this.dbg = dbg;
var serial = this;
this.timerReceiveData = this.cpu.addTimer(function() {
serial.printMessage("timerReceiveData()");
serial.receiveData()
});
this.chipset = /** @type {ChipSet} */ (cmp.getMachineComponent("ChipSet"));
bus.addPortInputTable(this, SerialPort.aPortInput, this.portBase);
bus.addPortOutputTable(this, SerialPort.aPortOutput, this.portBase);
this.initConnection();
this.setReady();
};
@ -555,9 +556,11 @@ SerialPort.prototype.getBaudTimeout = function(maskRate)
*/
SerialPort.prototype.receiveByte = function(b)
{
this.printMessage("receiveByte(" + str.toHexByte(b) + "): " + str.toHexByte(this.bStatus));
if (!(this.bStatus & SerialPort.UART8251.STATUS.RECV_FULL)) {
this.bDataIn = b;
this.bStatus |= SerialPort.UART8251.STATUS.RECV_FULL;
this.printMessage("receiveByte(" + str.toHexByte(b) + "): " + str.toHexByte(this.bStatus) + " (requesting interrupt)");
this.cpu.requestINTR(this.nIRQ);
return true;
}
@ -575,21 +578,8 @@ SerialPort.prototype.receiveData = function()
if (this.receiveByte(this.sDataReceived.charCodeAt(0))) {
this.sDataReceived = this.sDataReceived.substr(1);
}
/*
* TODO: If data has become undeliverable for some reason (eg, the Debugger has paused execution),
* we should stop setting timeouts, and add one or more notification mechanisms to kickstart it again.
*/
if (this.sDataReceived) {
/*
* TODO: setTimeout() is a less-than-ideal solution, because it's too slow; timeouts won't fire until
* the end of a CPU burst. So instead of calculating a number of milliseconds, we should calculate a
* number of CPU cycles, and create a CPU notification mechanism that calls us back after that many cycles
* have elapsed (and which will automatically shorten the current CPU burst as needed).
*
* This will also solve the other issue noted above, because if the CPU has been halted, it won't be
* generating any notifications either.
*/
setTimeout(this.fnCheckDataReceived, this.getBaudTimeout(SerialPort.UART8251.BAUDRATES.RECV_RATE));
if (this.sDataReceived && this.cpu) {
this.cpu.setTimer(this.timerReceiveData, this.getBaudTimeout(SerialPort.UART8251.BAUDRATES.RECV_RATE));
}
}
};