from nmigen.utils import log2_int
-__all__ = ["Cycle", "wishbone_layout", "make_wb_layout", "WishboneArbiter"]
+__all__ = ["Cycle", "make_wb_layout", "WishboneArbiter"]
class Cycle:
END = 7
-def make_wb_layout(addr_wid, mask_wid, data_wid):
+def make_wb_layout(spec, cti=True):
+ addr_wid, mask_wid, data_wid = spec.addr_wid, spec.mask_wid, spec.reg_wid
adr_lsbs = log2_int(mask_wid) # LSBs of addr covered by mask
- badwid = addr_wid-adr_lsbs # MSBs (not covered by mask)
+ badwid = spec.addr_wid-adr_lsbs # MSBs (not covered by mask)
- return [
+ res = [
("adr", badwid , DIR_FANOUT),
("dat_w", data_wid, DIR_FANOUT),
("dat_r", data_wid, DIR_FANIN),
("stb", 1, DIR_FANOUT),
("ack", 1, DIR_FANIN),
("we", 1, DIR_FANOUT),
- ("cti", 3, DIR_FANOUT),
- ("bte", 2, DIR_FANOUT),
("err", 1, DIR_FANIN)
]
-
-wishbone_layout = make_wb_layout(32, 4, 32)
+ if not cti:
+ return res
+ return res + [
+ ("cti", 3, DIR_FANOUT),
+ ("bte", 2, DIR_FANOUT),
+ ]
class WishboneArbiter(Elaboratable):
- def __init__(self):
- self.bus = Record(wishbone_layout)
+ def __init__(self, pspec):
+ self.bus = Record(make_wb_layout(pspec))
self._port_map = dict()
def port(self, priority):