forked from opendacs/PyHCL
1.0 KiB
1.0 KiB
| sort |
|---|
| 5 |
Bundle！
Description
The Bundle is a composite type that defines a group of named signals (of any PyHCL basic type) under a single name. It is similar to Chisel Bundle. Actually, in PyHCL's core library, IO is actually a Bundle and translate to FIRRTL later on. As a beginner of PyHCL, you could simply treat Bundle as the struct data structure of C/C++.
Declaration
The way we define a Bundle is similar to IO:
bun = Bundle(
x=U.w(16),
y=S.w(16),
z=Bool
)
x, y, and z are the subfield of Bundle. Bundle is a datatype, so it must used in a circuit element:
breg = Reg(Bundle(
x=U.w(16),
y=S.w(16),
z=Bool
))
We use . operator to access the subfield of the Bundle, similar to IO:
breg.x <<= U(12)
breg.y <<= S(4)
breg.z <<= Bool(False)
io.out <<= breg.x
Bundle is still an experimental feature of PyHCL, we suggest that you only include basic types in Bundle.