Maxim Integrated / OneWire

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Dependents:   MAXREFDES131_Qt_Demo MAX32630FTHR_iButton_uSD_Logger MAX32630FTHR_DS18B20_uSD_Logger MAXREFDES130_131_Demo ... more

Diff: OneWire_Masters/GPIO/owlink.s

Revision:
40:590791ecac1c
Parent:
31:7c684e49fa8f
Child:
46:afe466c96069
--- a/OneWire_Masters/GPIO/owlink.s	Tue Apr 05 18:43:39 2016 +0000
+++ b/OneWire_Masters/GPIO/owlink.s	Tue Apr 05 17:28:35 2016 -0500
@@ -1,4 +1,4 @@
-#define PROC_CLOCK_MHZ 24 // Processor clock in MHz
+#define PROC_CLOCK_MHZ (__SYSTEM_HFX / 1000000) // Processor clock in MHz
 #define OVERHEAD_TUNING 21 // Fraction where OverheadTime(us) = OVERHEAD_TUNING / PROC_CLOCK_MHZ
 // Make PROC_CLOCK_MHZ and OVERHEAD_TUNING divisible by PROC_CYCLES_PER_LOOP for best results
 
@@ -25,6 +25,8 @@
   EXPORT ow_usdelay
 ow_usdelay
 #endif
+  cmp R0, #0 // Return if time_us equals zero
+  beq return
   mov R1, #LOOPS_PER_US
   mul R0, R0, R1
   sub R0, R0, #LOOPS_REMOVED_TUNING
@@ -35,10 +37,15 @@
 #endif
   subs R0, R0, #1
   bne loop
+#ifdef TOOLCHAIN_GCC_ARM
+return:
+#else // TOOLCHAIN_IAR or TOOLCHAIN_ARM_STD
+return
+#endif
   bx R14
   
 #ifdef TOOLCHAIN_GCC_ARM
   .end
 #else // TOOLCHAIN_IAR or TOOLCHAIN_ARM_STD
   END
-#endif
\ No newline at end of file
+#endif