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#ifndef __INC_DELAY_H
#define __INC_DELAY_H
////////////////////////////////////////////////////////////////////////////////////////////
//
// Clock cycle counted delay loop
//
////////////////////////////////////////////////////////////////////////////////////////////
#if defined(__arm__)
# define NOP __asm__ __volatile__ ("nop\n");
# define NOP2 __asm__ __volatile__ ("nop\n\tnop");
#else
# define NOP __asm__ __volatile__ ("cp r0,r0\n");
# define NOP2 __asm__ __volatile__ ("rjmp .+0");
#endif
// predeclaration to not upset the compiler
template<int CYCLES> inline void delaycycles();
// TODO: ARM version of _delaycycles_
// worker template - this will nop for LOOP * 3 + PAD cycles total
template<int LOOP, int PAD> inline void _delaycycles_AVR() {
delaycycles<PAD>();
// the loop below is 3 cycles * LOOP. the LDI is one cycle,
// the DEC is 1 cycle, the BRNE is 2 cycles if looping back and
// 1 if not (the LDI balances out the BRNE being 1 cycle on exit)
__asm__ __volatile__ (
" LDI R16, %0\n"
"L_%=: DEC R16\n"
" BRNE L_%=\n"
: /* no outputs */
: "M" (LOOP)
: "r16"
);
}
// usable definition
#if !defined(__MK20DX128__)
template<int CYCLES> __attribute__((always_inline)) inline void delaycycles() {
_delaycycles_AVR<CYCLES / 3, CYCLES % 3>();
}
#else
template<int CYCLES> __attribute__((always_inline)) inline void delaycycles() {
NOP; delaycycles<CYCLES-1>();
}
#endif
// pre-instantiations for values small enough to not need the loop, as well as sanity holders
// for some negative values.
template<> __attribute__((always_inline)) inline void delaycycles<-6>() {}
template<> __attribute__((always_inline)) inline void delaycycles<-5>() {}
template<> __attribute__((always_inline)) inline void delaycycles<-4>() {}
template<> __attribute__((always_inline)) inline void delaycycles<-3>() {}
template<> __attribute__((always_inline)) inline void delaycycles<-2>() {}
template<> __attribute__((always_inline)) inline void delaycycles<-1>() {}
template<> __attribute__((always_inline)) inline void delaycycles<0>() {}
template<> __attribute__((always_inline)) inline void delaycycles<1>() {NOP;}
template<> __attribute__((always_inline)) inline void delaycycles<2>() {NOP2;}
template<> __attribute__((always_inline)) inline void delaycycles<3>() {NOP;NOP2;}
template<> __attribute__((always_inline)) inline void delaycycles<4>() {NOP2;NOP2;}
template<> __attribute__((always_inline)) inline void delaycycles<5>() {NOP2;NOP2;NOP;}
// Some timing related macros/definitions
// Macro to convert from nano-seconds to clocks and clocks to nano-seconds
// #define NS(_NS) (_NS / (1000 / (F_CPU / 1000000L)))
#if F_CPU < 96000000
#define NS(_NS) ( (_NS * (F_CPU / 1000000L))) / 1000
#define CLKS_TO_MICROS(_CLKS) ((long)(_CLKS)) / (F_CPU / 1000000L)
#else
#define NS(_NS) ( (_NS * (F_CPU / 2000000L))) / 1000
#define CLKS_TO_MICROS(_CLKS) ((long)(_CLKS)) / (F_CPU / 2000000L)
#endif
// Macro for making sure there's enough time available
#define NO_TIME(A, B, C) (NS(A) < 3 || NS(B) < 3 || NS(C) < 6)
#if defined(__MK20DX128__)
extern volatile uint32_t systick_millis_count;
# define MS_COUNTER systick_millis_count
#else
# if defined(CORE_TEENSY)
extern volatile unsigned long timer0_millis_count;
# define MS_COUNTER timer0_millis_count
# else
extern volatile unsigned long timer0_millis;
# define MS_COUNTER timer0_millis
# endif
#endif
#endif
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