Add read-multiplexer logic

Evaluating every single wire is maybe not the best way to do this, but
it is probably better than writing a very exotic SV construct with
(for-)loops, breaks, and a lot of conditions. Most synthesis tools are
pretty good at recognizing this case-construct and generating a good
mutliplexer.

srdl2sv/components/addrmap.py

@@ -69,6 +69,9 @@ class AddrMap(Component):
 
         self.logger.info("Done generating all child-regfiles/registers")
 
+        # Create RTL of all registers
+        [x.create_rtl() for x in self.registers.values()]
+
         # Add bus widget ports
         widget_rtl = self.__get_widget_ports_rtl()
 
@@ -159,9 +162,32 @@ class AddrMap(Component):
         # Append genvars
         self.__append_genvars()
 
+        # Create read multiplexer
+        self.__create_mux_string()
+
         # Add endmodule keyword
         self.rtl_footer.append('endmodule')
 
+    def __create_mux_string(self):
+        # TODO: Add variable for bus width
+        self.rtl_footer.append(
+            self.process_yaml(
+                AddrMap.templ_dict['read_mux'],
+                {'list_of_cases':
+                    '\n'.join([
+                        AddrMap.templ_dict['list_of_mux_cases']['rtl']
+                            .format(x[0][1]+x[1][0],
+                                    ''.join(
+                                        [x[0][0],
+                                         x[1][1]])) for y in self.children.values() \
+                                                        for x in y.create_mux_string()
+                        ])
+                }
+            )
+        )
+
+
+
     def __add_signal_instantiation(self):
         dict_list = [(key, value) for (key, value) in self.get_signals(True).items()]
         signal_width = min(max([len(value[0]) for (_, value) in dict_list]), 40)

srdl2sv/components/component.py

@@ -26,6 +26,7 @@ class Component():
         self.field_type = ''
 
         # Save object
+        # TODO: should probably be list because of alias registers
         self.obj = obj
 
         # Save name
@@ -100,14 +101,6 @@ class Component():
         rtl_children = []
 
         for x in self.children.values():
-            # In case of fields, the RTL must first be generated.
-            # Reason is that we only know at the very end whether
-            # all alias registers are processed for fields
-            try:
-                x.create_rtl()
-            except:
-                pass
-
             rtl_children.append(x.get_rtl())
 
         # Concatenate header, main, and footer

srdl2sv/components/field.py

@@ -155,10 +155,14 @@ class Field(Component):
         onread = obj.get_property('onread')
 
         access_rtl['sw_read'] = ([], False)
-        if obj.get_property('sw') in (AccessType.rw, AccessType.r) and onread:
+        if obj.get_property('sw') in (AccessType.rw, AccessType.r):
+            # Append to list of registers that can read
+            self.readable_by.add(path_wo_field)
+
+            # Set onread properties
             if onread == OnReadType.ruser:
-                self.logger.warning("The OnReadType.ruser is not yet supported!")
-            else:
+                self.logger.error("The OnReadType.ruser is not yet supported!")
+            elif onread:
                 access_rtl['sw_read'][0].append(
                     self.process_yaml(
                         Field.templ_dict[str(onread)],
@@ -412,6 +416,11 @@ class Field(Component):
         # Save byte boundaries
         self.lsbyte = math.floor(obj.inst.lsb / 8)
         self.msbyte = math.floor(obj.inst.msb / 8)
+        self.msb = obj.inst.msb
+        self.lsb = obj.inst.lsb
+
+        # Set that tells which hierarchies can read this field
+        self.readable_by = set()
 
         # Determine resets. This includes checking for async/sync resets,
         # the reset value, and whether the field actually has a reset

srdl2sv/components/regfile.py

@@ -122,6 +122,9 @@ class RegFile(Component):
             glbl_settings['generate_active'] = False
             self.rtl_footer.append("endgenerate")
 
+        # Create RTL of all registers
+        [x.create_rtl() for x in self.registers.values()]
+
     def __process_variables(self,
             obj: node.RegfileNode,
             parents_dimensions: list,
@@ -160,4 +163,7 @@ class RegFile(Component):
         genvars = ['[{}]'.format(chr(97+i)) for i in range(self.dimensions)]
         self.genvars_str = ''.join(genvars)
 
+    def create_mux_string(self):
+        for i in self.children.values():
+            yield from i.create_mux_string()
 

srdl2sv/components/register.py

@@ -2,6 +2,7 @@ import importlib.resources as pkg_resources
 import math
 import sys
 import yaml
+import itertools
 
 from systemrdl import node
 
@@ -28,8 +29,7 @@ class Register(Component):
         # Save and/or process important variables
         self.__process_variables(obj, parents_dimensions, parents_stride, glbl_settings)
 
-        # Create RTL for fields
-        # Fields should be in order in RTL, therefore, use list
+        # Create RTL for fields of initial, non-alias register
         for field in obj.fields():
             # Use range to save field in an array. Reason is, names are allowed to
             # change when using an alias
@@ -44,6 +44,9 @@ class Register(Component):
                 self.children[field_range].sanity_checks()
 
     def create_rtl(self):
+        # Create RTL of children
+        [x.create_rtl() for x in self.children.values()]
+
         # Create generate block for register and add comment
         if self.dimensions and not self.generate_active:
             self.rtl_header.append("generate")
@@ -69,15 +72,89 @@ class Register(Component):
         if self.dimensions and not self.generate_active:
             self.rtl_footer.append("endgenerate\n")
 
+        # Add assignment of read-wires
+        self.__add_sw_read_assignments()
+
+        # Add wire instantiation
+        self.__add_signal_instantiations()
+
         # Create comment and provide user information about register he/she is looking at
         self.rtl_header = [
             Register.templ_dict['reg_comment'].format(
-                name = obj.inst_name,
+                name = self.obj.inst_name,
                 dimensions = self.dimensions,
                 depth = self.depth),
                 *self.rtl_header
             ]
 
+    def __add_sw_read_assignments(self):
+        accesswidth = self.obj.get_property('accesswidth') - 1
+        self.rtl_footer.append("")
+
+        for x in self.name_addr_mappings:
+            current_bit = 0
+            list_of_fields = []
+            for y in self.children.values():
+                if x[0] in y.readable_by:
+                    empty_bits = y.lsb - current_bit
+                    current_bit = y.msb + 1
+
+                    if empty_bits > 0:
+                        list_of_fields.append("{}'b0".format(empty_bits))
+
+                    list_of_fields.append("{}_q".format(y.path_underscored))
+
+            empty_bits = accesswidth - current_bit + 1
+
+            if empty_bits > 0:
+                list_of_fields.append("{}'b0".format(empty_bits))
+
+            # Create list of mux-inputs to later be picked up by carrying addrmap
+            self.sw_read_assignment_var_name.append(
+                (
+                    self.process_yaml(
+                        Register.templ_dict['sw_read_assignment_var_name'],
+                        {'path': x[0],
+                         'accesswidth': accesswidth}
+                    ),
+                    x[1], # Start addr
+                )
+            )
+
+            self.rtl_footer.append(
+                self.process_yaml(
+                    Register.templ_dict['sw_read_assignment'],
+                    {'sw_read_assignment_var_name': self.sw_read_assignment_var_name[-1][0],
+                     'genvars': self.genvars_str,
+                     'list_of_fields': ', '.join(reversed(list_of_fields))}
+                )
+            )
+
+    def create_mux_string(self):
+        for mux_tuple in self.sw_read_assignment_var_name:
+            # Loop through lowest dimension and add stride of higher
+            # dimension once everything is processed
+            if self.total_array_dimensions:
+                vec = [0]*len(self.total_array_dimensions)
+
+                for i in self.eval_genvars(vec, 0, self.total_array_dimensions):
+                    yield (mux_tuple, i)
+
+    def eval_genvars(self, vec, depth, dimensions):
+        for i in range(dimensions[depth]):
+            vec[depth] = i
+
+            if depth == len(dimensions) - 1:
+                yield (
+                        eval(self.genvars_sum_str_vectorized),
+                        '[{}]'.format(']['.join(map(str, vec)))
+                      )
+            else:
+                yield from self.eval_genvars(vec, depth+1, dimensions)
+
+
+        vec[depth] = 0
+
     def __add_address_decoder(self):
         # Assign variables from bus
         self.obj.current_idx = [0]
@@ -98,8 +175,9 @@ class Register(Component):
                  'depth': self.depth,
                  'field_type': self.field_type}
             )
-        ) for i, x in enumerate(self.alias_names)]
+        ) for i, x in enumerate(self.name_addr_mappings)]
 
+    def __add_signal_instantiations(self):
         # Add wire/register instantiations
         dict_list = [(key, value) for (key, value) in self.get_signals().items()]
 
@@ -143,7 +221,8 @@ class Register(Component):
 
         # Add name to list
         self.obj.current_idx = [0]
-        self.alias_names.append((self.create_underscored_path_static(obj)[3], obj.absolute_address))
+        self.name_addr_mappings.append(
+            (self.create_underscored_path_static(obj)[3], obj.absolute_address))
 
     def __process_variables(
             self,
@@ -151,13 +230,15 @@ class Register(Component):
             parents_dimensions: list,
             parents_stride: list,
             glbl_settings: dict):
-        # Save object
-        self.obj = obj
 
         # Save name
         self.obj.current_idx = [0]
         self.name = obj.inst_name
-        self.alias_names = [(self.create_underscored_path_static(obj)[3], obj.absolute_address)]
+
+        # Create mapping between (alias-) name and address
+        self.name_addr_mappings = [
+            (self.create_underscored_path_static(obj)[3], obj.absolute_address)
+            ]
 
         # Create full name
         self.create_underscored_path()
@@ -165,6 +246,9 @@ class Register(Component):
         # Gnerate already started?
         self.generate_active = glbl_settings['generate_active']
 
+        # Empty array for mux-input signals
+        self.sw_read_assignment_var_name = []
+
         # Determine dimensions of register
         if obj.is_array:
             self.sel_arr = 'array'
@@ -183,7 +267,7 @@ class Register(Component):
             self.sel_arr = 'single'
             self.total_array_dimensions = parents_dimensions
             self.array_dimensions = []
-            self.total_stride = self.obj.array_stride
+            self.total_stride = parents_stride
 
         # How many dimensions were already part of some higher up hierarchy?
         self.parents_depths = len(parents_dimensions)
@@ -200,6 +284,7 @@ class Register(Component):
 
         # Determine value to compare address with
         genvars_sum = []
+        genvars_sum_vectorized = []
         try:
             for i, stride in enumerate(self.total_stride):
                 genvars_sum.append(chr(97+i))
@@ -207,7 +292,14 @@ class Register(Component):
                 genvars_sum.append(str(stride))
                 genvars_sum.append("+")
 
+                genvars_sum_vectorized.append('vec[')
+                genvars_sum_vectorized.append(str(i))
+                genvars_sum_vectorized.append(']*')
+                genvars_sum_vectorized.append(str(stride))
+                genvars_sum_vectorized.append("+")
+
             genvars_sum.pop()
+            genvars_sum_vectorized.pop()
 
             self.logger.debug(
                 "Multidimensional with dimensions '{}' and stride '{}'".format(
@@ -221,4 +313,5 @@ class Register(Component):
                 "Caugt expected IndexError because genvars_sum is empty")
 
         self.genvars_sum_str = ''.join(genvars_sum)
+        self.genvars_sum_str_vectorized = ''.join(genvars_sum_vectorized)
 

srdl2sv/components/templates/addrmap.yaml

@@ -48,3 +48,16 @@ enum_declaration:
 enum_var_list_item:
     rtl: |-
         {name:{max_name_width}} = {width}'d{value}
+read_mux:
+    rtl: |-
+
+      // Read multiplexer
+      always_comb
+      begin
+      case(addr)
+      {list_of_cases}
+      endcase
+      end
+list_of_mux_cases:
+    rtl: |-
+        32'd{}: sw_rd_bus = {};

srdl2sv/components/templates/regs.yaml

@@ -15,7 +15,7 @@ rw_wire_assign_1_dim:
     input_ports:
     output_ports:
 rw_wire_assign_multi_dim: 
-    rtl: |
+    rtl: |-
         // Register-activation for '{path}' {alias}
         assign {path}_accss{genvars} = addr == {addr}+({genvars_sum});
         assign {path}_sw_wr{genvars} = {path}_accss{genvars} && r_vld;
@@ -45,3 +45,12 @@ generate_for_end: |-
     end // of for loop with iterator {dimension}
 signal_declaration: |-
     {type:{signal_width}} {name:{name_width}}{unpacked_dim};
+sw_read_assignment_var_name:
+    rtl: |-
+        {path}_rd_mux_in
+    signals:
+        - name: '{path}_rd_mux_in'
+          signal_type: 'logic [{accesswidth}:0]'
+sw_read_assignment:
+    rtl: |-
+        assign {sw_read_assignment_var_name}{genvars} = {{{list_of_fields}}};

srdl2sv/components/widgets/amba3ahblite.yaml

@@ -16,6 +16,9 @@ module_instantiation:
              .byte_enable,
              .sw_wr_bus,
 
+             // Inputs from internal logic
+             .sw_rd_bus,
+ 
              // Bus protocol
              .HRESETn,
              .HCLK,
@@ -42,6 +45,8 @@ module_instantiation:
           signal_type: 'logic [ 3:0]'
         - name: 'sw_wr_bus'
           signal_type: 'logic [31:0]'
+        - name: 'sw_rd_bus'
+          signal_type: 'logic [31:0]'
     input_ports:
         - name: 'HRESETn'
           signal_type: ''