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@30:fdd7a0f82f2f, 2016-03-29 (annotated)

Committer:
IanBenzMaxim
Date:
Tue Mar 29 15:40:58 2016 +0000
Revision:
30:fdd7a0f82f2f
Parent:
29:5c51a17cfbf5
Child:
31:7c684e49fa8f
Switch on toolchain to enable ARM (armasm) and IAR assembler support. Still need support for GCC and armclang assemblers.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
IanBenzMaxim 28:057bb14d3cee 1 PROC_CLOCK_MHZ EQU 24 ; Processor clock in MHz
IanBenzMaxim 28:057bb14d3cee 2 OVERHEAD_TUNING EQU 21 ; Fraction where OverheadTime(us) = OVERHEAD_TUNING / PROC_CLOCK_MHZ
IanBenzMaxim 28:057bb14d3cee 3 ; Make PROC_CLOCK_MHZ and OVERHEAD_TUNING divisible by PROC_CYCLES_PER_LOOP for best results
IanBenzMaxim 28:057bb14d3cee 4
IanBenzMaxim 28:057bb14d3cee 5 PIPELINE_REFILL_PROC_CYCLES EQU 1 ; ARM specifies 1-3 cycles for pipeline refill following a branch
IanBenzMaxim 28:057bb14d3cee 6 PROC_CYCLES_PER_LOOP EQU (2 + PIPELINE_REFILL_PROC_CYCLES)
IanBenzMaxim 28:057bb14d3cee 7 LOOPS_PER_US EQU (PROC_CLOCK_MHZ / PROC_CYCLES_PER_LOOP) ; Number of loop passes for a 1 us delay
IanBenzMaxim 28:057bb14d3cee 8 LOOPS_REMOVED_TUNING EQU (OVERHEAD_TUNING / PROC_CYCLES_PER_LOOP)
IanBenzMaxim 30:fdd7a0f82f2f 9
IanBenzMaxim 30:fdd7a0f82f2f 10 #ifdef TOOLCHAIN_IAR
IanBenzMaxim 30:fdd7a0f82f2f 11 SECTION owlink : CODE
IanBenzMaxim 30:fdd7a0f82f2f 12 #else
IanBenzMaxim 29:5c51a17cfbf5 13 AREA owlink, CODE
IanBenzMaxim 30:fdd7a0f82f2f 14 #endif
IanBenzMaxim 28:057bb14d3cee 15
IanBenzMaxim 28:057bb14d3cee 16 ; void ow_usdelay(unsigned int time_us)
IanBenzMaxim 29:5c51a17cfbf5 17 EXPORT ow_usdelay
IanBenzMaxim 29:5c51a17cfbf5 18 ow_usdelay
IanBenzMaxim 28:057bb14d3cee 19 mov R1, #LOOPS_PER_US
IanBenzMaxim 28:057bb14d3cee 20 mul R0, R0, R1
IanBenzMaxim 28:057bb14d3cee 21 sub R0, R0, #LOOPS_REMOVED_TUNING
IanBenzMaxim 29:5c51a17cfbf5 22 loop
IanBenzMaxim 28:057bb14d3cee 23 subs R0, R0, #1
IanBenzMaxim 28:057bb14d3cee 24 bne loop
IanBenzMaxim 28:057bb14d3cee 25 bx R14
IanBenzMaxim 28:057bb14d3cee 26
IanBenzMaxim 28:057bb14d3cee 27 END