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runtime_library:os:start [2020/12/10 18:38] – [Interrupts] ursgrafruntime_library:os:start [2021/12/27 15:27] (current) – [System Sanity Checks] ursgraf
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 You can program the processor either using interrupts in a foreground/background system or means of an operating system. Some classes will be linked and loaded in either case. This is true for the class ''Kernel'' for basic initializations, the class ''Heap'' for dynamic memory allocation and the classes for exception handling. \\ You can program the processor either using interrupts in a foreground/background system or means of an operating system. Some classes will be linked and loaded in either case. This is true for the class ''Kernel'' for basic initializations, the class ''Heap'' for dynamic memory allocation and the classes for exception handling. \\
 When choosing an operating system you can select a simple, robust and very efficient non-preemtive tasking system (class ''Task''). The very popular MicroC/OSII will be also available on request. When choosing an operating system you can select a simple, robust and very efficient non-preemtive tasking system (class ''Task''). The very popular MicroC/OSII will be also available on request.
-The minimum task period is limited to one millisecond. For fast control applications you can use the decrementer on the PowerPC architecture as a fast running timer and produce exceptions at a very high frequency.+The minimum task period is limited to one millisecond. For fast control applications you can use the decrementer on the PowerPC architecture or on the Zynq7000 platform as a fast running timer and produce exceptions at a very high frequency.
 The basic modules are all written in Java. All the necessary hardware resources can be accessed through special built-in methods. The basic modules are all written in Java. All the necessary hardware resources can be accessed through special built-in methods.
  
Line 14: Line 14:
  
 <code java> <code java>
-public class TestTask extends Task{+public class TestTask extends Task {
  
- public void action () { +  public void action () { 
- // put task code here +    // put task code here 
- }+  }
   
- static {  +  static {  
- Task task1 = new TestTask();  +    Task task1 = new TestTask();  
- task1.period = 500; // call twice per second +    task1.period = 500; // call twice per second 
- Task.install(task1); +    Task.install(task1); 
- }+  }
 } }
 </code> </code>
  
 ===== Interrupts ===== ===== Interrupts =====
-A processor might have some sort of a hardware priorization scheme when dealing with interrupts. Some of the potential internal and external interrupt sources use vectoring or get vectored to the same memory location and are dealt with by a software scheduler. You have to assign a priority level to each of the interrupts. A low level means a high priority. In order to achieve highest efficiency, interrupt nesting is switched off. That makes it necessary to write small interrupt service routines.+A processor might have some sort of a hardware priorization scheme when dealing with interrupts. Some of the potential internal and external interrupt sources use vectoring or get vectored to the same memory location and are dealt with by a software scheduler. You have to assign a priority level to each of the interrupts. A low level means a high priority. In order to achieve highest efficiency, interrupt nesting is switched off. That makes it necessary to write small interrupt service routines. Further, never allocate objects within an interrupt routine or in a method called by an interrupt routine, because the heap allocation methods are not thread safe for efficiency reasons. 
 + 
 +==== Interrupts in the ARM Architecture ==== 
 +=== Zynq7000 Interrupts === 
 +A Zynq7000 processor has private peripheral and shared peripheral interrupts and assigns each peripheral a interrupt number, see the [[https://wiki.bu.ost.ch/infoportal/embedded_systems/zynq7000/start|Zynq 7000 Technical Reference Manual]], table 7-4.   
 + 
 +<code java> 
 +public class IntTest extends IrqInterrupt{ 
 + 
 +  public void action() { 
 +    // put your code here 
 +    US.PUT4(IsrReg, (1 << BitNum)); // clear interrupt status bit 
 +  } 
 + 
 +  static { 
 +    IntTest int = new IntTest();  
 +    IrqInterrupt.install(int, num);  // num must be equal to the assigned number for this peripheral 
 +  } 
 +} 
 +</code>
  
 ==== Interrupts in the PowerPC Architecture ==== ==== Interrupts in the PowerPC Architecture ====
Line 38: Line 57:
 public class IntTest extends Interrupt { public class IntTest extends Interrupt {
  
- public void action() { +  public void action() { 
- // put your code here +    // put your code here 
- }+  }
  
- static { +  static { 
- IntTest int = new IntTest();  +    IntTest int = new IntTest();  
- int.enableRegAdr = registername; int.enBit = bitnumber; +    int.enableRegAdr = registername; int.enBit = bitnumber; 
- int.flagRegAdr = registername; int.flag = bitnumber; +    int.flagRegAdr = registername; int.flag = bitnumber; 
- Interrupt.install(int, 5, true); +    Interrupt.install(int, 5, true); 
- }+  }
 } }
 </code> </code>
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 public class ExtIntTest extends Interrupt { public class ExtIntTest extends Interrupt {
  
- public void action() { +  public void action() { 
- // put your code here +    // put your code here 
- }+  }
  
- static { +  static { 
- ExtIntTest int5 = new ExtIntTest();  +    ExtIntTest int5 = new ExtIntTest();  
- Interrupt.install(int5, 5, false); +    Interrupt.install(int5, 5, false); 
- }+  }
 } }
 </code> </code>
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 <code java> <code java>
 void MyExampleMethod () { void MyExampleMethod () {
- ... +  ... 
- US.PUTSPR(EID, 0); // switch off interrupts globally +  US.PUTSPR(EID, 0); // switch off interrupts globally 
- ... // critical section +  ... // critical section 
- US.PUTSPR(EIE, 0); // interrupts reenabled  +  US.PUTSPR(EIE, 0); // interrupts reenabled  
- ...+  ...
 } }
 </code> </code>
Line 88: Line 107:
 <code java> <code java>
 public class DecrementerTest extends Decrementer { public class DecrementerTest extends Decrementer {
- static int count;+  static int count;
  
- public void action() { +  public void action() { 
- // put your code here +    // put your code here 
- }+  }
  
- static { +  static { 
- DecrementerTest d = new DecrementerTest(); +    DecrementerTest d = new DecrementerTest(); 
- d.decPeriodUs = 1000000; // period is 1 s +    d.decPeriodUs = 1000000; // period is 1 s 
- Decrementer.install(d); +    Decrementer.install(d); 
- }+  }
 } }
 </code> </code>
Line 108: Line 127:
  
 =====System Sanity Checks ===== =====System Sanity Checks =====
-  - The stack size is set by the configuration. In order to check, whether this size is enough at all times for a running system, you can call a target command //ch.ntb.inf.deep.runtime.mpc555.Kernel.checkStack//. If the stack size was ever bigger than the maximum stack size this check fails and the LED on the 555 board starts blinking. +  * The stack size is set by the configuration. In order to check, whether this size is enough at all times for a running system, you can call a target command in your kernel, e.g. //org.deepjava.runtime.mpc555.Kernel.checkStack//. \\ If the stack size was ever bigger than the maximum stack size this check fails and the signalling LED on the board starts blinking, see [[runtime_library:exceptions:start#signaling_with_led|Signaling with LED]]. 
-  - The heap manager includes an automatic garbage collection. If the heap gets too fragmented or to large chunks of heap memory are requested and no free block can be found, the LED on the 555 board starts blinking and programm excecution stops.+  * The heap manager includes an automatic garbage collection. If the heap gets too fragmented or to large chunks of heap memory are requested and no free block can be found, the signaling LED on the board starts blinking and program execution stops, see [[runtime_library:exceptions:start#signaling_with_led|Signaling with LED]].
  
runtime_library/os/start.1607621914.txt.gz · Last modified: 2020/12/10 18:38 by ursgraf

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