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Merge pull request #18 from izuannazrin/master

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Interrupt bit support for ACIA
This commit is contained in:
Seth Morabito 2017-06-04 18:53:44 -07:00 committed by GitHub
commit 3c3aee30a7
3 changed files with 45 additions and 23 deletions
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31
src/main/java/com/loomcom/symon/devices/Acia.java
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@ -33,7 +33,7 @@ import com.loomcom.symon.exceptions.MemoryRangeException;
public abstract class Acia extends Device {
private String name;
/**
* Register addresses
*/
@ -42,13 +42,14 @@ public abstract class Acia extends Device {
boolean receiveIrqEnabled = false;
boolean transmitIrqEnabled = false;
boolean overrun = false;
long lastTxWrite = 0;
boolean interrupt = false;
long lastTxWrite = 0;
long lastRxRead = 0;
int baudRate = 0;
long baudRateDelay = 0;
/**
/**
* Read/Write buffers
*/
int rxChar = 0;
@ -56,8 +57,8 @@ public abstract class Acia extends Device {
boolean rxFull = false;
boolean txEmpty = true;
public Acia(int address, int size, String name) throws MemoryRangeException {
super(address, address + size - 1, name);
this.name = name;
@ -100,7 +101,7 @@ public abstract class Acia extends Device {
/**
* @return The contents of the status register.
*/
public abstract int statusReg();
public abstract int statusReg(boolean cpuAccess);
@Override
public String toString() {
@ -117,13 +118,14 @@ public abstract class Acia extends Device {
}
public synchronized void rxWrite(int data) {
if(rxFull) {
if (rxFull) {
overrun = true;
}
rxFull = true;
if (receiveIrqEnabled) {
interrupt = true;
getBus().assertIrq();
}
@ -132,11 +134,12 @@ public abstract class Acia extends Device {
public synchronized int txRead(boolean cpuAccess) {
if (cpuAccess) {
txEmpty = true;
txEmpty = true;
if (transmitIrqEnabled) {
getBus().assertIrq();
}
if (transmitIrqEnabled) {
interrupt = true;
getBus().assertIrq();
}
}
return txChar;
}

15
src/main/java/com/loomcom/symon/devices/Acia6551.java
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@ -61,7 +61,7 @@ public class Acia6551 extends Acia {
case DATA_REG:
return rxRead(cpuAccess);
case STAT_REG:
return statusReg();
return statusReg(cpuAccess);
case CMND_REG:
return commandRegister;
case CTRL_REG:
@ -178,8 +178,8 @@ public class Acia6551 extends Acia {
* @return The contents of the status register.
*/
@Override
public int statusReg() {
// TODO: Parity Error, Framing Error, DTR, DSR, and Interrupt flags.
public int statusReg(boolean cpuAccess) {
// TODO: Parity Error, Framing Error, DTR, and DSR flags.
int stat = 0;
if (rxFull && System.nanoTime() >= (lastRxRead + baudRateDelay)) {
stat |= 0x08;
@ -190,6 +190,14 @@ public class Acia6551 extends Acia {
if (overrun) {
stat |= 0x04;
}
if (interrupt) {
stat |= 0x80;
}
if (cpuAccess) {
interrupt = false;
}
return stat;
}
@ -201,6 +209,7 @@ public class Acia6551 extends Acia {
rxFull = false;
receiveIrqEnabled = false;
transmitIrqEnabled = false;
interrupt = false;
}
}

22
src/main/java/com/loomcom/symon/devices/Acia6850.java
View File

@ -43,7 +43,7 @@ public class Acia6850 extends Acia {
static final int STAT_REG = 0; // read-only
static final int CTRL_REG = 0; // write-only
static final int RX_REG = 1; // read-only
static final int TX_REG = 1; // write-only
@ -56,9 +56,12 @@ public class Acia6850 extends Acia {
public int read(int address, boolean cpuAccess) throws MemoryAccessException {
switch (address) {
case RX_REG:
if (cpuAccess) {
interrupt = false;
}
return rxRead(cpuAccess);
case STAT_REG:
return statusReg();
return statusReg(cpuAccess);
default:
throw new MemoryAccessException("No register.");
@ -69,6 +72,9 @@ public class Acia6850 extends Acia {
public void write(int address, int data) throws MemoryAccessException {
switch (address) {
case TX_REG:
if (cpuAccess) {
interrupt = false;
}
txWrite(data);
break;
case CTRL_REG:
@ -78,7 +84,7 @@ public class Acia6850 extends Acia {
throw new MemoryAccessException("No register.");
}
}
private void setCommandRegister(int data) {
// Bits 0 & 1 control the master reset
if((data & 0x01) != 0 && (data & 0x02) != 0) {
@ -97,8 +103,8 @@ public class Acia6850 extends Acia {
* @return The contents of the status register.
*/
@Override
public int statusReg() {
// TODO: Parity Error, Framing Error, DTR, DSR, and Interrupt flags.
public int statusReg(boolean cpuAccess) {
// TODO: Parity Error, Framing Error, DTR, and DSR flags.
int stat = 0;
if (rxFull && System.nanoTime() >= (lastRxRead + baudRateDelay)) {
stat |= 0x01;
@ -109,7 +115,10 @@ public class Acia6850 extends Acia {
if (overrun) {
stat |= 0x20;
}
if (interrupt) {
stat |= 0x80;
}
return stat;
}
@ -118,6 +127,7 @@ public class Acia6850 extends Acia {
overrun = false;
rxFull = false;
txEmpty = true;
interrupt = false;
}
}