MMU: get store to activate only when data is available, and to wait till done

[soc.git] / src / soc / fu / mmu / fsm.py

diff --git a/src/soc/fu/mmu/fsm.py b/src/soc/fu/mmu/fsm.py
index b7ee3d578acb1a199b5542c4cf28375c48aac020..812736d6bf3c4be6b4be449398e6c48afb4a756e 100644 (file)
--- a/src/soc/fu/mmu/fsm.py
+++ b/src/soc/fu/mmu/fsm.py
@@ -57,11 +57,11 @@ class LoadStore1(PortInterfaceBase):
         #m.d.comb += self.l_in.valid.eq(1)
         #m.d.comb += self.l_in.addr.eq(addr)
         #m.d.comb += self.l_in.load.eq(0)
-        m.d.comb += self.d_valid.eq(1)
-        m.d.comb += self.d_in.valid.eq(self.d_validblip)
         m.d.comb += self.d_in.load.eq(0)
         m.d.comb += self.d_in.byte_sel.eq(mask)
         m.d.comb += self.d_in.addr.eq(addr)
+        # TEMPORARY BAD HACK! disable the cache entirely for read
+        m.d.comb += self.d_in.nc.eq(1)
         return None
 
     def set_rd_addr(self, m, addr, mask):
@@ -80,15 +80,20 @@ class LoadStore1(PortInterfaceBase):
         # this is for peripherals.  same thing done in Microwatt loadstore1.vhdl
         with m.If(addr[28:] == Const(0xc, 4)):
             m.d.comb += self.d_in.nc.eq(1)
+        # TEMPORARY BAD HACK! disable the cache entirely for read
+        m.d.comb += self.d_in.nc.eq(1)
         return None #FIXME return value
 
     def set_wr_data(self, m, data, wen):
+        # do the "blip" on write data
+        m.d.comb += self.d_valid.eq(1)
+        m.d.comb += self.d_in.valid.eq(self.d_validblip)
         # put data into comb which is picked up in main elaborate()
         m.d.comb += self.d_w_valid.eq(1)
         m.d.comb += self.d_w_data.eq(data)
         #m.d.sync += self.d_in.byte_sel.eq(wen) # this might not be needed
-        #st_ok = self.d_out.valid # TODO indicates write data is valid
-        st_ok = Const(1, 1)
+        st_ok = self.d_out.valid # TODO indicates write data is valid
+        #st_ok = Const(1, 1)
         return st_ok
 
     def get_rd_data(self, m):