[7efcefa] | 1 | |
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| 2 | -- This is an example of how to attach and handle interrupts in Ada 95. |
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| 3 | -- Interrupt handling is done as follows: |
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| 4 | -- |
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| 5 | -- 1. A protected procedure is attached to the interrupt |
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| 6 | -- 2. When activated, the procedure enables a conditional entry |
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| 7 | -- 3. A task waiting on the entry will carry out the work. |
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| 8 | -- |
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| 9 | -- In this way, we spend minimum amount of time in the protected |
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| 10 | -- procedure. Many other schemes are of course possible... |
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| 11 | -- |
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| 12 | -- Written by Tullio Vardanega and Jiri Gaisler |
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| 13 | -- European Space Agency, 1999. |
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| 14 | -- |
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[14f44a3] | 15 | -- The license and distribution terms for this file may be |
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| 16 | -- found in the file LICENSE in this distribution or at |
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| 17 | -- http://www.rtems.com/license/LICENSE. |
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| 18 | -- |
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| 19 | -- $Id$ |
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| 20 | -- |
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| 21 | |
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[7efcefa] | 22 | |
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| 23 | |
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| 24 | with Ada.Interrupts; |
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| 25 | with System; |
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| 26 | with Ada.Text_IO; |
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[14f44a3] | 27 | with Ada.Real_Time; use Ada.Real_Time; |
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[7efcefa] | 28 | |
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| 29 | package body Interrupt_pkg is |
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| 30 | |
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| 31 | type T_SEM is (HIGH, LOW); |
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| 32 | |
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| 33 | Protected_Priority : constant System.Interrupt_Priority := |
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| 34 | System.Interrupt_Priority'First; |
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| 35 | |
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[14f44a3] | 36 | Start_Time : Ada.Real_Time.Time; |
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| 37 | Stop_Time : Ada.Real_Time.Time; |
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| 38 | |
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[7efcefa] | 39 | -- Protected object, including interrupt handler (Signal) and conditional entry. |
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| 40 | |
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| 41 | protected Handler is |
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| 42 | procedure Signal; |
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| 43 | entry Wait; |
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| 44 | pragma Attach_Handler (Signal, 17); -- Signal 17 equals irq 1 on ERC32 |
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| 45 | pragma Priority (Protected_Priority); |
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| 46 | private |
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| 47 | BARRIER : T_SEM := HIGH; |
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| 48 | end Handler; |
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| 49 | |
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| 50 | protected body Handler is |
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| 51 | procedure Signal is |
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| 52 | begin |
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| 53 | BARRIER := LOW; |
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| 54 | end Signal; |
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[14f44a3] | 55 | |
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[7efcefa] | 56 | entry Wait when (BARRIER = LOW) is |
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[14f44a3] | 57 | Took : Time_Span; |
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[7efcefa] | 58 | begin |
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[14f44a3] | 59 | Stop_Time := Ada.Real_Time.Clock; |
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[7efcefa] | 60 | BARRIER := HIGH; |
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[14f44a3] | 61 | |
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| 62 | Took := Stop_Time - Start_Time; |
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| 63 | |
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| 64 | Ada.Text_IO.Put_line ( "Interrupt took: " & |
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| 65 | Duration'Image(To_Duration(Took))); |
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[7efcefa] | 66 | end Wait; |
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| 67 | end Handler; |
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| 68 | |
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| 69 | -- Sporadic task, waiting on entry (Wait) for the interrupt. |
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| 70 | |
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| 71 | task sporadic is |
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[14f44a3] | 72 | pragma Priority (100); |
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[7efcefa] | 73 | end sporadic; |
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| 74 | |
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| 75 | task body sporadic is |
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[14f44a3] | 76 | Message : constant STRING := "sporadic activated"; |
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[7efcefa] | 77 | begin |
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| 78 | loop |
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| 79 | Handler.Wait; |
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[14f44a3] | 80 | |
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[7efcefa] | 81 | end loop; |
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| 82 | end sporadic; |
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| 83 | |
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| 84 | -- Test program, generating interrupt 1 on ERC32 |
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| 85 | |
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| 86 | procedure itest is |
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| 87 | procedure irqforce(irq : integer); |
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| 88 | pragma Import (C, irqforce, "irqforce"); |
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| 89 | begin |
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[14f44a3] | 90 | |
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| 91 | Start_Time := Ada.Real_Time.Clock; |
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| 92 | Stop_Time := Ada.Real_Time.Clock; |
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| 93 | |
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| 94 | Ada.Text_IO.Put_line ( "Timer Overhead: " & |
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| 95 | Duration'Image(To_Duration(Stop_Time - Start_Time))); |
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| 96 | |
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[7efcefa] | 97 | for i in 1..10 loop |
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[14f44a3] | 98 | Start_Time := Ada.Real_Time.Clock; |
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[7efcefa] | 99 | irqforce(1); |
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| 100 | delay(0.05); |
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| 101 | end loop; |
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| 102 | |
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| 103 | -- Have to kill sporadic to exit since it is has an infinite loop |
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| 104 | abort sporadic; |
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| 105 | end; |
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| 106 | |
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| 107 | begin |
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| 108 | |
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[14f44a3] | 109 | -- itest; |
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| 110 | NULL; |
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[7efcefa] | 111 | |
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| 112 | end Interrupt_pkg; |
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| 113 | |
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| 114 | |
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