This can cause confusion:
* If the erroneous object is None, it is printed as 'None', which
appears as a string (and could be the result of converting None
to a string.)
* If the erroneous object is a string, it is printed as ''<val>'',
which is a rather strange combination of quotes.
Although useful for debugging, most external tools often complain
about such attributes (with notable exception of Vivado). As such,
it is better to emit Verilog with these attributes into a separate
file such as `design.debug.v` and only emit the attributes that were
explicitly placed by the user to `design.v`.
This still leaves the (*init*) attribute. See #220 for details.
Also, replace `bits, sign = x.shape()` with more idiomatic
`width, signed = x.shape()`.
This unifies all properties corresponding to `len(x)` to `x.width`.
(Not all values have a `width` property.)
Fixes#210.
This is a somewhat obscure use case, but it is possible to use async
functions with pysim by carefully using @asyncio.coroutine. That is,
async functions can call back into pysim if they are declared in
a specific way:
@asyncio.coroutine
def do_something(self, value):
yield self.reg.eq(value)
which may then be called from elsewhere with:
async def test_case(self):
await do_something(0x1234)
This approach is unfortunately limited in that async functions
cannot yield directly. It should likely be improved by using async
generators, but supporting coroutines in pysim is unobtrustive and
allows existing code that made use of this feature in oMigen to work.
Because Fragment.prepare is not (currently) idempotent, it is useful
to be able to avoid calling it when converting. Even if it is made
idempotent, it can be slow on large designs, so it is advantageous
regardless of that.
Using 'x is legal RTLIL, in theory, but in practice it crashes Yosys
and when it doesn't, it causes Yosys to produce invalid Verilog.
Using a dummy wire is always safe and is not a major readability
issue as this is a rare corner case.
(It is not trivial to shorten the RHS in this case, because during
expansion of an ArrayProxy, match_shape() could be called in
a context far from the RHS handling logic.)
This might help with propagation of locations through optimizer
passes, since not all of them take care to preserve cells at all,
but usually wires stay intact when possible.
Also fixes incorrect source location on value.part().
This gives particularly pathological results on IO buffers, like:
connect \D_OUT_0 \user_led_0_user_led_0__o
Since subfragment signals are name-prefixed because this works well
for signals propagated upwards across hierarchy, this is never
desirable for instances.
