1
0
mirror of https://github.com/myhdl/myhdl.git synced 2025-01-24 21:52:56 +08:00
myhdl/example/manual/shadow.py
Josy Boelen a9d65c0f87
Class based design (#447)
* 1) added J. Villars code from PR#238 (https://github.com/myhdl/myhdl/pull/328)  to augment the `@block` decorator with arguments, initially to keep the generated names simpler especially when nesting `block`s without adding *hdl* code - I modified it a bit using `skipname=False` rather than `keepname=True` as default
2) added _hdlclass.py to support Class Based Design, look at bot test/conversion/general/test_hdlclass.py and test/conversion/general/test_hdlclass2.py
This needed the changes of 1) above.

* 1) _Signal.py
added property `.nbits` for use in HDL iso `len(sig)`, anticipating Structure and Array where `len()` is not what `.nbits` will give you ...
added `duplicate(value=None)` method to avoid that ugly `newsig = Signal(oldsig._val)`
2) _block.py
minor changes
3)_hdlclass.py
removed ForwardPorts resolution as this currently adds a *stray* sig in the .vcd output - even if noe ForwardPorts are present
cleaned the code to what is actually working
4) _traceSignals.py
The `@block(skipname=True), which is heavily used in Class Based Design, applies `None` as that block-name and this will show up as an additional level in the .vcd which looks ugly and distracting.
So reworked this file to skip adding the None-level
Also added indents in the .vcd var section, primarily for debugging, but kept this as it looks nice.
Introduce f'strings
5) _analyze.py
changed UPPER_CASE naming of processe/always into lower case, making the generated signals conform with the producing process/always
6) test_xxxx.py
changed @instance with *logic* as function name into *comb* as `logic` has become a reserved Verilog keyword

* cleaned test/bugs
replacing generator names *logic* and *output* with *comb* as `logic` and `output` have become Verilog reserved keywords

* replacing more occurrences of *logic* by either *comb* or *synch*

* one *comb* too many :(

* added small test_hdlclass0.py to help in debugging
updated the 'doc' section -- needs publishing
added direct conversion of Class Based Design modules - resulting in lesss boiler-plate code
2024-12-21 17:21:11 +01:00

52 lines
1.1 KiB
Python

import myhdl
from myhdl import *
from random import randrange
def arbiter(grant_vector, request_vector):
@always_comb
def comb():
grant_vector.next = 0
for i in range(len(request_vector)):
if request_vector[i] == 1:
grant_vector.next[i] = 1
break
return comb
def check():
M = 8
request_list = [Signal(bool()) for i in range(M)]
request_vector = ConcatSignal(*reversed(request_list))
grant_vector = Signal(intbv(0)[M:])
grant_list = [grant_vector(i) for i in range(M)]
arb = arbiter(grant_vector, request_vector)
@instance
def stimulus():
for i in range(100):
for j in range(M):
request_list[j].next = randrange(2)
yield delay(10)
if 1 in request_list:
assert grant_list.index(1) == request_list.index(1)
assert grant_list.count(0) == M - 1
# print bin(grant_vector, 8), bin(request_vector, 8)
raise StopSimulation()
return arb, stimulus
sim = Simulation(check())
sim.run()