From bb37de8eb4410a088a83d884ebc24a005caebb7c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mike=20Schw=C3=B6rer?= <mailport@mikescher.de>
Date: Tue, 16 May 2017 10:11:35 +0200
Subject: [PATCH] Timer interrupt

---
 PIC_Simulator/PIC/PICProgramm.cs | 19 ++++++++++++++++++-
 PIC_Simulator/PIC/PICTimer.cs    |  2 +-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/PIC_Simulator/PIC/PICProgramm.cs b/PIC_Simulator/PIC/PICProgramm.cs
index aa0a8e6..9a2b686 100644
--- a/PIC_Simulator/PIC/PICProgramm.cs
+++ b/PIC_Simulator/PIC/PICProgramm.cs
@@ -66,6 +66,8 @@ namespace PIC_Simulator.PIC
 		public const uint INTCON_BIT_INTF = 1;		// RB0/INT Interrupt Flag Bit
 		public const uint INTCON_BIT_RBIF = 0;		// RB Port Change Interrupt Flag Bit
 
+		public const uint INTERRUPT_SERVICE_ADDRESS = 0x04;
+
 
 		public const string ADDWF  = "000111dfffffff";
 		public const string ANDWF  = "000101dfffffff";
@@ -650,6 +652,7 @@ namespace PIC_Simulator.PIC
 
 				Stack.Push((uint) PCCounter);
 				PCCounter = (int) (aktueller_befehl.parameter_k - 1);
+				cycleCount = 2;
 			}
 			else if (aktueller_befehl.befehl == CLRWDT)
 			{
@@ -710,7 +713,9 @@ namespace PIC_Simulator.PIC
 				// (INTCON < 7 >).This is a two cycle
 				// instruction.
 
-				//TODO
+				PCCounter = (int) Stack.Pop();
+				SetRegisterOhneBank(ADDR_INTCON, INTCON_BIT_GIE, true);
+				cycleCount = 2;
 			}
 			else if (aktueller_befehl.befehl == RETLW)
 			{
@@ -981,5 +986,17 @@ namespace PIC_Simulator.PIC
 
 			PCCounter = 0;
 		}
+
+		public void TimerInterrupt()
+		{
+			if (!GetRegisterOhneBank(ADDR_INTCON, INTCON_BIT_GIE)) return;
+			if (!GetRegisterOhneBank(ADDR_INTCON, INTCON_BIT_T0IE)) return;
+
+			SetRegisterOhneBank(ADDR_INTCON, INTCON_BIT_T0IF, true);
+			SetRegisterOhneBank(ADDR_INTCON, INTCON_BIT_GIE, false);
+
+			Stack.Push((uint)PCCounter);
+			PCCounter = (int) INTERRUPT_SERVICE_ADDRESS;
+		}
 	}
 }
diff --git a/PIC_Simulator/PIC/PICTimer.cs b/PIC_Simulator/PIC/PICTimer.cs
index 89f5c53..c52c0e7 100644
--- a/PIC_Simulator/PIC/PICTimer.cs
+++ b/PIC_Simulator/PIC/PICTimer.cs
@@ -59,7 +59,7 @@ namespace PIC_Simulator.PIC
 				uint Result = current + 1;
 				if (Result > 0xFF)
 				{
-					//TODO Interrupt PIT_TIMER
+					programm.TimerInterrupt();
 				}
 
 				Result %= 0x100;