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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");
#else
# define NOP __asm__ __volatile__ ("cp r0,r0\n");
#endif
// predeclaration to not upset the compiler
template<int CYCLES> inline void delaycycles();
// TODO: ARM version of _delaycycles_
// usable definition
#if defined(FASTLED_AVR)
// 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"
);
}
template<int CYCLES> __attribute__((always_inline)) inline void delaycycles() {
_delaycycles_AVR<CYCLES / 3, CYCLES % 3>();
}
#else
// template<int LOOP, int PAD> inline void _delaycycles_ARM() {
// 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__ (
// " mov.w r9, %0\n"
// "L_%=: subs.w r9, r9, #1\n"
// " bne.n L_%=\n"
// : /* no outputs */
// : "M" (LOOP)
// : "r9"
// );
// }
template<int CYCLES> __attribute__((always_inline)) inline void delaycycles() {
// _delaycycles_ARM<CYCLES / 3, CYCLES % 3>();
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<-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>() {NOP;NOP;}
template<> __attribute__((always_inline)) inline void delaycycles<3>() {NOP;NOP;NOP;}
template<> __attribute__((always_inline)) inline void delaycycles<4>() {NOP;NOP;NOP;NOP;}
template<> __attribute__((always_inline)) inline void delaycycles<5>() {NOP;NOP;NOP;NOP;NOP;}
#ifdef __SAM3X8E__
class SysClockSaver {
SysTick_Type m_Saved;
public:
SysClockSaver(int newTimeValue) { save(newTimeValue); }
void save(int newTimeValue) {
m_Saved.CTRL = SysTick->CTRL;
SysTick->CTRL &= ~(SysTick_CTRL_TICKINT_Msk | SysTick_CTRL_ENABLE_Msk);
m_Saved.LOAD = SysTick->LOAD;
m_Saved.VAL = SysTick->VAL;
SysTick->VAL = 0;
SysTick->LOAD = newTimeValue;
SysTick->CTRL |= SysTick_CTRL_CLKSOURCE_Msk;
SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk;
}
void restore() {
SysTick->CTRL &= ~(SysTick_CTRL_TICKINT_Msk | SysTick_CTRL_ENABLE_Msk);
SysTick->LOAD = m_Saved.LOAD;
SysTick->VAL = m_Saved.VAL;
SysTick->CTRL = m_Saved.CTRL;
}
};
#endif
#endif
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