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fixed a possible Bug in PulseBlaster

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WAIT opcode is ignored if preceeding state is shorter than 120ns.
This commit is contained in:
Markus Rosenstihl 2017-01-16 16:01:31 +00:00
parent 974be4ec82
commit 64fb1ed1fe
1 changed files with 12 additions and 3 deletions
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15
drivers/SpinCore-PulseBlaster/SpinCore-PulseBlaster.cpp
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@ -173,18 +173,27 @@ void SpinCorePulseBlaster::run_pulse_program_w_sync(state& exp, double sync_freq
prog->push_front(c); prog->push_front(c);
// first command: wait for monoflop on P136 up again // first command: wait for monoflop on P136 up again
// the monoflop will open if ADC sample clock goes through zero voltage
// this synchronizes the start of the pulse program with the sampling clock
c=prog->create_command(); c=prog->create_command();
c->ttls=sync_mask; c->ttls=sync_mask;
c->instruction=SpinCorePulseBlaster::WAIT; c->instruction=SpinCorePulseBlaster::WAIT;
c->length=shortest_pulse; c->length=shortest_pulse;
prog->push_front(c); prog->push_front(c);
if (0) {
// zeroth command: set sync mask in advance, sometimes necessary
if (1) {
// zeroth command: pulse before WAIT opcode needs to be at least 120ns
// otherwise the WAIT is ignored and the program keeps repeating until pb_stop()
// reported to SpinCore (Contact Request 2016-12-19 at 1482143561)
// markusro: When is this necessary? (TODO)
c=prog->create_command(); c=prog->create_command();
c->ttls=sync_mask; c->ttls=sync_mask;
c->instruction=SpinCorePulseBlaster::CONTINUE; c->instruction=SpinCorePulseBlaster::CONTINUE;
c->length=shortest_pulse+2; //c->length=shortest_pulse+2; // markusro: why +2 ??
c->length=12; // markusro: why +2 ??
prog->push_front(c); prog->push_front(c);
} }
duration+=2.0*shortest_pulse/clock+1.0/sync_freq; duration+=2.0*shortest_pulse/clock+1.0/sync_freq;