def handshake_signals(self) -> Iterator[Union[ast.Wire, ast.Reg]]:
"""All handshake signals used for this instance.
Yields:
Union[ast.Wire, ast.Reg] of signals.
"""
if self.is_autorun:
yield ast.Reg(name=self.start.name, width=None)
else:
yield ast.Wire(name=self.start.name, width=None)
yield ast.Reg(name=self.state.name, width=ast.make_width(2))
yield from (ast.Wire(name=rtl.wire_name(self.name, suffix),
width=None)
for suffix in rtl.HANDSHAKE_OUTPUT_PORTS)
def __init__(self, name: str, level: int, width: Optional[int] = None):
self.level = level
self._ids = tuple(
ast.Identifier(f'{name}__q%d' % i) for i in range(level + 1))
self._width: Optional[ast.Width] = width and ast.make_width(width)
def _instantiate_global_fsm(
self,
task: Task,
is_done_signals: List[rtl.Pipeline],
) -> None:
# global state machine
def is_state(state: ast.IntConst) -> ast.Eq:
return ast.Eq(left=rtl.STATE, right=state)
def set_state(state: ast.IntConst) -> ast.NonblockingSubstitution:
return ast.NonblockingSubstitution(left=rtl.STATE, right=state)
countdown = ast.Identifier('countdown')
countdown_width = (self.register_level - 1).bit_length()
task.module.add_signals([
ast.Reg(rtl.STATE.name, width=ast.make_width(2)),
ast.Reg(countdown.name, width=ast.make_width(countdown_width)),
])
state01_action = set_state(STATE10)
if is_done_signals:
state01_action = ast.make_if_with_block(
cond=ast.make_operation(
operator=ast.Land,
nodes=(x[-1] for x in reversed(is_done_signals)),
),
true=state01_action,
)
global_fsm = ast.make_case_with_block(
comp=rtl.STATE,
cases=[
(
STATE00,
ast.make_if_with_block(
cond=self.start_q[-1],
true=set_state(STATE01),
),
),
(
STATE01,
state01_action,
),
(
STATE10,
[
set_state(STATE11 if self.register_level else STATE00),
ast.NonblockingSubstitution(
left=countdown,
right=ast.make_int(max(0,
self.register_level - 1)),
),
],
),
(
STATE11,
ast.make_if_with_block(
cond=ast.Eq(
left=countdown,
right=ast.make_int(0, width=countdown_width),
),
true=set_state(STATE00),
false=ast.NonblockingSubstitution(
left=countdown,
right=ast.Minus(
left=countdown,
right=ast.make_int(1, width=countdown_width),
),
),
),
),
],
)
task.module.add_logics([
ast.Always(
sens_list=rtl.CLK_SENS_LIST,
statement=ast.make_block(
ast.make_if_with_block(
cond=rtl.RST,
true=set_state(STATE00),
false=global_fsm,
)),
),
ast.Assign(left=rtl.IDLE, right=is_state(STATE00)),
ast.Assign(left=rtl.DONE, right=self.done_q[-1]),
ast.Assign(left=rtl.READY, right=self.done_q[0]),
])
task.module.add_pipeline(self.start_q, init=rtl.START)
task.module.add_pipeline(self.done_q, init=is_state(STATE10))