From a28cbb81b2a151999f75dae825107aaecae427a2 Mon Sep 17 00:00:00 2001
From: Tobias <tm@tm3d.de>
Date: Fri, 18 Sep 2015 20:14:28 +0200
Subject: [PATCH] Handle Overflow of Timer by Reset dedection (Problem was wenn
 Reset comes verry soon after or in communication. (DS18B20 and Onewireviewer
 sometimes))

---
 common/OWPinInterrupt.s   |  1 +
 common/OWSet_ATTINYX4.s   | 13 +++++++++++--
 common/OWTimerInterrupt.s |  6 +++++-
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/common/OWPinInterrupt.s b/common/OWPinInterrupt.s
index 660c7f3..b5b7b87 100644
--- a/common/OWPinInterrupt.s
+++ b/common/OWPinInterrupt.s
@@ -143,6 +143,7 @@ no_zerromaker:
 	sts sendflag,r_sendflag
 	sts bcount,r_bcount
 	sts rwbyte,r_rwbyte
+	//cdb
 	pop r_sendflag
 	pop r_rwbyte
 	pop r_bcount
diff --git a/common/OWSet_ATTINYX4.s b/common/OWSet_ATTINYX4.s
index c0a074b..de42063 100644
--- a/common/OWSet_ATTINYX4.s
+++ b/common/OWSet_ATTINYX4.s
@@ -37,6 +37,7 @@
 #define OW_DDR _SFR_IO_ADDR(DDRB)  //pin direction register
 #define TCNT_REG _SFR_IO_ADDR(TCNT0)
 
+
 #define DB_PORT _SFR_IO_ADDR(PORTB) //DEBUG
 #define DB_PIN _SFR_IO_ADDR(PINB) //DEBUG
 #define DB_DDR _SFR_IO_ADDR(DDRB) //DEBUG
@@ -60,14 +61,22 @@
 //#define OWT_WRITE 18
 //#define OWT_READ 4
 
-#define OWT_MIN_RESET 80 
-#define OWT_RESET2 100
+#define OWT_MIN_RESET 120
+#define OWT_RESET2 80
 #define OWT_RESET_PRESENT 30
 #define OWT_PRESENT 130
 #define OWT_WRITE 35
 #define OWT_READ 12
 
+.macro CLEAR_TOV_FLAG
+	ldi r_temp,1
+	out _SFR_IO_ADDR(TIFR0),r_temp
+.endm
 
+.macro JMP_NO_TOV
+	in r_temp, _SFR_IO_ADDR(TIFR0)
+	sbrc r_temp,TOV0 ; wenn ueberlauf gleiich weiter
+.endm
 
 .macro CLEAR_INTERRUPT_FLAG 
 	ldi r_temp,(1<<INTF0);inerrupt flags durch 1 loeschen..... 0 macht nix
diff --git a/common/OWTimerInterrupt.s b/common/OWTimerInterrupt.s
index cd8af1c..504a68b 100644
--- a/common/OWTimerInterrupt.s
+++ b/common/OWTimerInterrupt.s
@@ -32,7 +32,7 @@
 
 
 .global TIMER_INTERRUPT
-	TIMER_INTERRUPT:
+TIMER_INTERRUPT:
 	push r_temp
 	in r_temp,_SFR_IO_ADDR(SREG)  
 	push r_temp
@@ -40,12 +40,16 @@
 	rjmp tint_end ; Leitung 1 kein Reset
 	ldi r_temp,0  
 	out TCNT_REG,r_temp
+	CLEAR_TOV_FLAG
 tint_loop_rend:
 	sbis OW_PIN,OW_PINN ;warten bis leitung wieder h 
 	rjmp tint_loop_rend
+	JMP_NO_TOV ;ueberspringe wenn kein ueberlauf
+	rjmp tint_overrun
 	in r_temp,TCNT_REG ;schauen ob es lange genug gedauert hat fuer reset
 	cpi r_temp,OWT_RESET2 
 	brlo tint_end
+tint_overrun:
 	ldi r_temp,0
 	out TCNT_REG,r_temp
 	;zwischen Reset und Presets
-- 
2.34.1