from nmutil.latch import SRLatch
-class DepCell(Elaboratable):
+class DependencyRow(Elaboratable):
""" implements 11.4.7 mitch alsup dependence cell, p27
adjusted to be clock-sync'd on rising edge only.
mitch design (as does 6600) requires alternating rising/falling clock
asynchronous) would be reset at the exact moment that GO was requested,
and the RSEL would be garbage.
"""
- def __init__(self, llen):
- self.llen = llen
- # inputs
- self.reg_i = Signal(llen, reset_less=True) # reg bit in (top)
- self.issue_i = Signal(reset_less=True) # Issue in (top)
- self.hazard_i = Signal(llen, reset_less=True) # to check hazard
- self.go_i = Signal(reset_less=True) # Go read/write in (left)
- self.die_i = Signal(reset_less=True) # Die in (left)
- self.q_o = Signal(llen, reset_less=True) # Latch out (reg active)
-
- # for Register File Select Lines (vertical)
- self.rsel_o = Signal(llen, reset_less=True) # reg sel (bottom)
- # for Function Unit "forward progress" (horizontal)
- self.fwd_o = Signal(llen, reset_less=True) # FU forard progress (right)
-
- def elaborate(self, platform):
- m = Module()
- m.submodules.l = l = SRLatch(sync=False, llen=self.llen) # async latch
-
- # reset on go HI, set on dest and issue
- m.d.comb += l.s.eq(Repl(self.issue_i, self.llen) & self.reg_i)
- m.d.comb += l.r.eq(Repl(self.go_i | self.die_i, self.llen))
-
- # Function Unit "Forward Progress".
- m.d.comb += self.fwd_o.eq((l.q) & self.hazard_i) # & ~self.issue_i)
-
- # Register Select. Activated on go read/write and *current* latch set
- m.d.comb += self.q_o.eq(l.qlq)
- m.d.comb += self.rsel_o.eq(l.qlq & Repl(self.go_i, self.llen))
-
- return m
-
- def __iter__(self):
- yield self.reg_i
- yield self.hazard_i
- yield self.issue_i
- yield self.go_i
- yield self.die_i
- yield self.q_o
- yield self.rsel_o
- yield self.fwd_o
-
- def ports(self):
- return list(self)
-
-
-class DependencyRow(Elaboratable):
- """ implements 11.4.7 mitch alsup dependence cell, p27
- """
- def __init__(self, n_reg):
+ def __init__(self, n_reg, n_src):
self.n_reg = n_reg
+ self.n_src = n_src
+ # arrays
+ src = []
+ rsel = []
+ fwd = []
+ for i in range(n_src):
+ j = i + 1 # name numbering to match src1/src2
+ src.append(Signal(n_reg, name="src%d" % j, reset_less=True))
+ rsel.append(Signal(n_reg, name="src%d_rsel_o" % j, reset_less=True))
+ fwd.append(Signal(n_reg, name="src%d_fwd_o" % j, reset_less=True))
+
# inputs
self.dest_i = Signal(n_reg, reset_less=True) # Dest in (top)
- self.src1_i = Signal(n_reg, reset_less=True) # oper1 in (top)
- self.src2_i = Signal(n_reg, reset_less=True) # oper2 in (top)
+ self.src_i = Array(src) # operands in (top)
self.issue_i = Signal(reset_less=True) # Issue in (top)
self.rd_pend_i = Signal(n_reg, reset_less=True) # Read pend in (top)
self.wr_pend_i = Signal(n_reg, reset_less=True) # Write pend in (top)
- self.rd_rsel_o = Signal(n_reg, reset_less=True) # Read pend out (bot)
- self.wr_rsel_o = Signal(n_reg, reset_less=True) # Write pend out (bot)
+ self.v_rd_rsel_o = Signal(n_reg, reset_less=True) # Read pend out (bot)
+ self.v_wr_rsel_o = Signal(n_reg, reset_less=True) # Write pend out (bot)
self.go_wr_i = Signal(reset_less=True) # Go Write in (left)
self.go_rd_i = Signal(reset_less=True) # Go Read in (left)
# for Register File Select Lines (vertical)
self.dest_rsel_o = Signal(n_reg, reset_less=True) # dest reg sel (bot)
- self.src1_rsel_o = Signal(n_reg, reset_less=True) # src1 reg sel (bot)
+ self.src_rsel_o = Array(rsel) # src reg sel (bot)
self.src2_rsel_o = Signal(n_reg, reset_less=True) # src2 reg sel (bot)
# for Function Unit "forward progress" (horizontal)
self.dest_fwd_o = Signal(n_reg, reset_less=True) # dest FU fw (right)
- self.src1_fwd_o = Signal(n_reg, reset_less=True) # src1 FU fw (right)
- self.src2_fwd_o = Signal(n_reg, reset_less=True) # src2 FU fw (right)
+ self.src_fwd_o = Array(fwd) # src FU fw (right)
def elaborate(self, platform):
m = Module()
- m.submodules.dest_c = dest_c = DepCell(self.n_reg)
- m.submodules.src1_c = src1_c = DepCell(self.n_reg)
- m.submodules.src2_c = src2_c = DepCell(self.n_reg)
-
- # connect issue and die
- for c in [dest_c, src1_c, src2_c]:
- m.d.comb += c.issue_i.eq(self.issue_i)
- m.d.comb += c.die_i.eq(self.go_die_i)
+ m.submodules.dest_c = dest_c = SRLatch(sync=False, llen=self.n_reg)
+ src_c = []
+ for i in range(self.n_src):
+ src_l = SRLatch(sync=False, llen=self.n_reg)
+ setattr(m.submodules, "src%d_c" % (i+1), src_l)
+ src_c.append(src_l)
# connect go_rd / go_wr (dest->wr, src->rd)
- m.d.comb += dest_c.go_i.eq(self.go_wr_i)
- m.d.comb += src1_c.go_i.eq(self.go_rd_i)
- m.d.comb += src2_c.go_i.eq(self.go_rd_i)
+ wr_die = Signal(reset_less=True)
+ rd_die = Signal(reset_less=True)
+ m.d.comb += wr_die.eq(self.go_wr_i | self.go_die_i)
+ m.d.comb += rd_die.eq(self.go_rd_i | self.go_die_i)
+ m.d.comb += dest_c.r.eq(Repl(wr_die, self.n_reg))
+ for i in range(self.n_src):
+ m.d.comb += src_c[i].r.eq(Repl(rd_die, self.n_reg))
# connect input reg bit (unary)
- for c, reg in [(dest_c, self.dest_i),
- (src1_c, self.src1_i),
- (src2_c, self.src2_i)]:
- m.d.comb += c.reg_i.eq(reg)
-
- # wark-wark: yes, writing to the same reg you are reading is *NOT*
- # a write-after-read hazard.
- selfhazard = Signal(self.n_reg, reset_less=False)
- m.d.comb += selfhazard.eq((self.dest_i & self.src1_i) |
- (self.dest_i & self.src2_i))
+ i_ext = Repl(self.issue_i, self.n_reg)
+ m.d.comb += dest_c.s.eq(i_ext & self.dest_i)
+ for i in range(self.n_src):
+ m.d.comb += src_c[i].s.eq(i_ext & self.src_i[i])
# connect up hazard checks: read-after-write and write-after-read
- m.d.comb += dest_c.hazard_i.eq(self.rd_pend_i) # read-after-write
- m.d.comb += src1_c.hazard_i.eq(self.wr_pend_i) # write-after-read
- m.d.comb += src2_c.hazard_i.eq(self.wr_pend_i) # write-after-read
+ m.d.comb += self.dest_fwd_o.eq(dest_c.q & self.rd_pend_i)
+ for i in range(self.n_src):
+ m.d.comb += self.src_fwd_o[i].eq(src_c[i].q & self.wr_pend_i)
- # connect fwd / reg-sel outputs
- for c, fwd, rsel in [(dest_c, self.dest_fwd_o, self.dest_rsel_o),
- (src1_c, self.src1_fwd_o, self.src1_rsel_o),
- (src2_c, self.src2_fwd_o, self.src2_rsel_o)]:
- m.d.comb += fwd.eq(c.fwd_o)
- m.d.comb += rsel.eq(c.rsel_o)
+ # connect reg-sel outputs
+ rd_ext = Repl(self.go_rd_i, self.n_reg)
+ wr_ext = Repl(self.go_wr_i, self.n_reg)
+ m.d.comb += self.dest_rsel_o.eq(dest_c.qlq & wr_ext)
+ for i in range(self.n_src):
+ m.d.comb += self.src_rsel_o[i].eq(src_c[i].qlq & rd_ext)
# to be accumulated to indicate if register is in use (globally)
# after ORing, is fed back in to rd_pend_i / wr_pend_i
- m.d.comb += self.rd_rsel_o.eq(src1_c.q_o | src2_c.q_o)
- #with m.If(~selfhazard):
- m.d.comb += self.wr_rsel_o.eq(dest_c.q_o)
+ src_q = []
+ for i in range(self.n_src):
+ src_q.append(src_c[i].qlq)
+ m.d.comb += self.v_rd_rsel_o.eq(Cat(*src_q).bool())
+ m.d.comb += self.v_wr_rsel_o.eq(dest_c.qlq)
return m
def __iter__(self):
yield self.dest_i
- yield self.src1_i
- yield self.src2_i
+ yield from self.src_i
yield self.rd_pend_i
yield self.wr_pend_i
yield self.issue_i
yield self.go_rd_i
yield self.go_die_i
yield self.dest_rsel_o
- yield self.src1_rsel_o
- yield self.src2_rsel_o
+ yield from self.src_rsel_o
yield self.dest_fwd_o
- yield self.src1_fwd_o
- yield self.src2_fwd_o
+ yield from self.src_fwd_o
def ports(self):
return list(self)
yield
def test_dcell():
- dut = DependencyRow(4)
+ dut = DependencyRow(4, 2)
vl = rtlil.convert(dut, ports=dut.ports())
with open("test_drow.il", "w") as f:
f.write(vl)
projects / soc.git / blobdiff