Merge pull request #1173 from sergachev/ecp5_delay

clock/lattice_ecp5: add ECP5 dynamic delay DELAYF primitive support
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enjoy-digital 2022-01-25 10:44:53 +01:00 committed by GitHub
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@ -165,3 +165,51 @@ class ECP5PLL(Module):
if f > 0: # i.e. not a feedback-only clock
self.params["attr"].append((f"FREQUENCY_PIN_CLKO{n_to_l[n]}", str(f/1e6)))
self.specials += Instance("EHXPLLL", **self.params)
class ECP5Delay(Module):
# from ECP5 docs
delay_step_s = 25e-12
n_steps = 128
def __init__(self):
self.i = Signal()
self.o = Signal()
self.value = Signal(max=self.n_steps)
def do_finalize(self):
rst = Signal()
move = Signal()
current_value = Signal(max=self.n_steps)
self.specials += Instance(
"DELAYF",
p_DEL_MODE="USER_DEFINED",
p_DEL_VALUE=self.value.reset,
i_A=self.i,
o_Z=self.o,
i_LOADN=~(ResetSignal() | rst),
i_MOVE=move,
i_DIRECTION=0,
o_CFLAG=Signal()
)
self.submodules.fsm = fsm = FSM()
fsm.act("WAIT",
If(self.value != current_value,
NextState('RST'))
)
fsm.act("RST",
rst.eq(1),
NextValue(current_value, 0),
NextState("MOVE")
)
fsm.act("MOVE",
If(current_value == self.value,
NextValue(move, 0),
NextState("WAIT")
).Else(
NextValue(move, ~move),
If(move,
NextValue(current_value, current_value + 1)),
))