Maxim Integrated / OneWire

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Dependents:   MAXREFDES131_Qt_Demo MAX32630FTHR_iButton_uSD_Logger MAX32630FTHR_DS18B20_uSD_Logger MAXREFDES130_131_Demo ... more

OneWire_Masters/GPIO/owlink.s@46:afe466c96069, 2016-04-06 (annotated)

Committer:
IanBenzMaxim
Date:
Wed Apr 06 10:06:06 2016 -0500
Revision:
46:afe466c96069
Parent:
40:590791ecac1c
Child:
52:4cba20c21941
Begin formalizing macros to write code for assemblers with different syntax.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
IanBenzMaxim 40:590791ecac1c 1 #define PROC_CLOCK_MHZ (__SYSTEM_HFX / 1000000) // Processor clock in MHz
IanBenzMaxim 31:7c684e49fa8f 2 #define OVERHEAD_TUNING 21 // Fraction where OverheadTime(us) = OVERHEAD_TUNING / PROC_CLOCK_MHZ
IanBenzMaxim 31:7c684e49fa8f 3 // Make PROC_CLOCK_MHZ and OVERHEAD_TUNING divisible by PROC_CYCLES_PER_LOOP for best results
IanBenzMaxim 28:057bb14d3cee 4
IanBenzMaxim 31:7c684e49fa8f 5 #define PIPELINE_REFILL_PROC_CYCLES 1 // ARM specifies 1-3 cycles for pipeline refill following a branch
IanBenzMaxim 31:7c684e49fa8f 6 #define PROC_CYCLES_PER_LOOP (2 + PIPELINE_REFILL_PROC_CYCLES)
IanBenzMaxim 31:7c684e49fa8f 7 #define LOOPS_PER_US (PROC_CLOCK_MHZ / PROC_CYCLES_PER_LOOP) // Number of loop passes for a 1 us delay
IanBenzMaxim 31:7c684e49fa8f 8 #define LOOPS_REMOVED_TUNING (OVERHEAD_TUNING / PROC_CYCLES_PER_LOOP)
IanBenzMaxim 46:afe466c96069 9
IanBenzMaxim 46:afe466c96069 10 // LABEL macro
IanBenzMaxim 46:afe466c96069 11 #ifdef TOOLCHAIN_GCC_ARM
IanBenzMaxim 46:afe466c96069 12 #define LABEL(x) x:
IanBenzMaxim 46:afe466c96069 13 #else // TOOLCHAIN_IAR or TOOLCHAIN_ARM_STD
IanBenzMaxim 46:afe466c96069 14 #define LABEL(x) x
IanBenzMaxim 46:afe466c96069 15 #endif
IanBenzMaxim 46:afe466c96069 16
IanBenzMaxim 46:afe466c96069 17 // EXPORT_LABEL macro
IanBenzMaxim 46:afe466c96069 18 #ifdef TOOLCHAIN_GCC_ARM
IanBenzMaxim 46:afe466c96069 19 #define EXPORT_LABEL(x) .global x
IanBenzMaxim 46:afe466c96069 20 #else // TOOLCHAIN_IAR or TOOLCHAIN_ARM_STD
IanBenzMaxim 46:afe466c96069 21 #define EXPORT_LABEL(x) EXPORT x
IanBenzMaxim 46:afe466c96069 22 #endif
IanBenzMaxim 46:afe466c96069 23
IanBenzMaxim 46:afe466c96069 24 // THUMB_FUNC macro
IanBenzMaxim 46:afe466c96069 25 #ifdef TOOLCHAIN_GCC_ARM
IanBenzMaxim 46:afe466c96069 26 #define THUMB_FUNC .thumb_func
IanBenzMaxim 46:afe466c96069 27 #else // TOOLCHAIN_IAR or TOOLCHAIN_ARM_STD
IanBenzMaxim 46:afe466c96069 28 #define THUMB_FUNC
IanBenzMaxim 46:afe466c96069 29 #endif
IanBenzMaxim 30:fdd7a0f82f2f 30
IanBenzMaxim 31:7c684e49fa8f 31 #if defined TOOLCHAIN_IAR
IanBenzMaxim 30:fdd7a0f82f2f 32 SECTION owlink : CODE
IanBenzMaxim 31:7c684e49fa8f 33 #elif defined TOOLCHAIN_ARM_STD
IanBenzMaxim 29:5c51a17cfbf5 34 AREA owlink, CODE
IanBenzMaxim 31:7c684e49fa8f 35 #else // TOOLCHAIN_GCC_ARM
IanBenzMaxim 31:7c684e49fa8f 36 .syntax unified
IanBenzMaxim 31:7c684e49fa8f 37 .section .text
IanBenzMaxim 30:fdd7a0f82f2f 38 #endif
IanBenzMaxim 28:057bb14d3cee 39
IanBenzMaxim 31:7c684e49fa8f 40 // void ow_usdelay(unsigned int time_us)
IanBenzMaxim 46:afe466c96069 41 THUMB_FUNC
IanBenzMaxim 46:afe466c96069 42 EXPORT_LABEL(ow_usdelay)
IanBenzMaxim 46:afe466c96069 43 LABEL(ow_usdelay)
IanBenzMaxim 40:590791ecac1c 44 cmp R0, #0 // Return if time_us equals zero
IanBenzMaxim 40:590791ecac1c 45 beq return
IanBenzMaxim 28:057bb14d3cee 46 mov R1, #LOOPS_PER_US
IanBenzMaxim 28:057bb14d3cee 47 mul R0, R0, R1
IanBenzMaxim 28:057bb14d3cee 48 sub R0, R0, #LOOPS_REMOVED_TUNING
IanBenzMaxim 46:afe466c96069 49 LABEL(loop)
IanBenzMaxim 28:057bb14d3cee 50 subs R0, R0, #1
IanBenzMaxim 28:057bb14d3cee 51 bne loop
IanBenzMaxim 46:afe466c96069 52 LABEL(return)
IanBenzMaxim 28:057bb14d3cee 53 bx R14
IanBenzMaxim 28:057bb14d3cee 54
IanBenzMaxim 31:7c684e49fa8f 55 #ifdef TOOLCHAIN_GCC_ARM
IanBenzMaxim 31:7c684e49fa8f 56 .end
IanBenzMaxim 31:7c684e49fa8f 57 #else // TOOLCHAIN_IAR or TOOLCHAIN_ARM_STD
IanBenzMaxim 31:7c684e49fa8f 58 END
IanBenzMaxim 40:590791ecac1c 59 #endif