+ # on a go_read, tell the ALU we're accepting data.
+ # NOTE: this spells TROUBLE if the ALU isn't ready!
+ # go_read is only valid for one clock!
+ with m.If(self.go_rd_i): # src operands ready, GO!
+ with m.If(~self.alu.p_ready_o): # no ACK yet
+ m.d.comb += self.alu.p_valid_i.eq(1) # so indicate valid
+
+ # put the register directly onto the output
+ comb += self.data_o.eq(data_r)