*
* Ad-hoc implementation of a Verilog preprocessor. The directives `define,
* `include, `ifdef, `ifndef, `else and `endif are handled here. All other
- * directives are handled by the lexer (see lexer.l).
+ * directives are handled by the lexer (see verilog_lexer.l).
*
*/
*
* A simple lexer for Verilog code. Non-preprocessor compiler directives are
* handled here. The preprocessor stuff is handled in preproc.cc. Everything
- * else is left to the bison parser (see parser.y).
+ * else is left to the bison parser (see verilog_parser.y).
*
*/
\begin{sloppypar}
The Verilog Lexer is written using the lexer generator {\it flex} \citeweblink{flex}. Its source code
-can be found in {\tt frontends/verilog/lexer.l} in the Yosys source tree.
+can be found in {\tt frontends/verilog/verilog\_lexer.l} in the Yosys source tree.
The lexer does little more than identifying all keywords and literals
recognised by the Yosys Verilog frontend.
\end{sloppypar}
\subsection{The Verilog Parser}
The Verilog Parser is written using the parser generator {\it bison} \citeweblink{bison}. Its source code
-can be found in {\tt frontends/verilog/parser.y} in the Yosys source tree.
+can be found in {\tt frontends/verilog/verilog\_parser.y} in the Yosys source tree.
It generates an AST using the \lstinline[language=C++]{AST::AstNode} data structure
defined in {\tt frontends/ast/ast.h}. An \lstinline[language=C++]{AST::AstNode} object has
In special cases such as synthesis for coarse-grain cell libraries or when
testing new synthesis algorithms it might be necessary to write a custom HDL
-synthesis tool or add new features to an existing one. It this cases the
+synthesis tool or add new features to an existing one. In these cases the
availability of a Free and Open Source (FOSS) synthesis tool that can be used
as basis for custom tools would be helpful.
dict<string, int> min_limits, max_limits;
bool or_next_if_better, make_transp, make_outreg;
char shuffle_enable;
+ vector<vector<std::tuple<bool,IdString,Const>>> attributes;
};
dict<IdString, vector<bram_t>> brams;
continue;
}
+ if (GetSize(tokens) >= 2 && tokens[0] == "attribute") {
+ data.attributes.emplace_back();
+ for (int idx = 1; idx <= GetSize(tokens)-1; idx++) {
+ size_t c1 = tokens[idx][0] == '!' ? 1 : 0;
+ size_t c2 = tokens[idx].find("=");
+ bool exists = (c1 == 0);
+ IdString key = RTLIL::escape_id(tokens[idx].substr(c1, c2));
+ Const val = c2 != std::string::npos ? tokens[idx].substr(c2+1) : RTLIL::Const(1);
+
+ data.attributes.back().emplace_back(exists, key, val);
+ }
+ continue;
+ }
+
syntax_error();
}
}
if (match.make_transp && wr_ports <= 1) {
pi.make_transp = true;
if (pi.clocks != 0) {
- if (wr_ports == 1 && wr_clkdom != clkdom) {
+ if (wr_ports == 1 && wr_clkdom != clkdom) {
log(" Bram port %c%d.%d cannot have soft transparency logic added as read and write clock domains differ.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1);
goto skip_bram_rport;
}
return false;
}
+ for (const auto &sums : match.attributes) {
+ bool found = false;
+ for (const auto &term : sums) {
+ bool exists = std::get<0>(term);
+ IdString key = std::get<1>(term);
+ const Const &value = std::get<2>(term);
+ auto it = cell->attributes.find(key);
+ if (it == cell->attributes.end()) {
+ if (exists)
+ continue;
+ found = true;
+ break;
+ }
+ else if (!exists)
+ continue;
+ if (it->second != value)
+ continue;
+ found = true;
+ break;
+ }
+ if (!found) {
+ std::stringstream ss;
+ bool exists = std::get<0>(sums.front());
+ if (!exists)
+ ss << "!";
+ IdString key = std::get<1>(sums.front());
+ ss << key.str();
+ const Const &value = std::get<2>(sums.front());
+ if (exists)
+ ss << "=";
+ if (value != Const(1))
+ ss << "\"" << value.decode_string() << "\"";
+
+ log(" Rule for bram type %s rejected: requirement 'attribute %s ...' not met.\n",
+ log_id(match.name), ss.str().c_str());
+ return false;
+ }
+ }
+
if (mode == 1)
return true;
}
goto next_match_rule;
}
+ for (const auto &sums : match.attributes) {
+ bool found = false;
+ for (const auto &term : sums) {
+ bool exists = std::get<0>(term);
+ IdString key = std::get<1>(term);
+ const Const &value = std::get<2>(term);
+ auto it = cell->attributes.find(key);
+ if (it == cell->attributes.end()) {
+ if (exists)
+ continue;
+ found = true;
+ break;
+ }
+ else if (!exists)
+ continue;
+ if (it->second != value)
+ continue;
+ found = true;
+ break;
+ }
+ if (!found) {
+ std::stringstream ss;
+ bool exists = std::get<0>(sums.front());
+ if (!exists)
+ ss << "!";
+ IdString key = std::get<1>(sums.front());
+ ss << key.str();
+ const Const &value = std::get<2>(sums.front());
+ if (exists)
+ ss << "=";
+ if (value != Const(1))
+ ss << "\"" << value.decode_string() << "\"";
+
+ log(" Rule for bram type %s (variant %d) rejected: requirement 'attribute %s ...' not met.\n",
+ log_id(bram.name), bram.variant, ss.str().c_str());
+ goto next_match_rule;
+ }
+ }
+
log(" Rule #%d for bram type %s (variant %d) accepted.\n", i+1, log_id(bram.name), bram.variant);
if (or_next_if_better || !best_rule_cache.empty())
log(" dcells ....... number of cells in 'data-direction'\n");
log(" cells ........ total number of cells (acells*dcells*dups)\n");
log("\n");
+ log("A match containing the command 'attribute' followed by a list of space\n");
+ log("separated 'name[=string_value]' values requires that the memory contains any\n");
+ log("one of the given attribute name and string values (where specified), or name\n");
+ log("and integer 1 value (if no string_value given, since Verilog will interpret\n");
+ log("'(* attr *)' as '(* attr=1 *)').\n");
+ log("A name prefixed with '!' indicates that the attribute must not exist.\n");
+ log("\n");
log("The interface for the created bram instances is derived from the bram\n");
log("description. Use 'techmap' to convert the created bram instances into\n");
log("instances of the actual bram cells of your target architecture.\n");
{
cover_list("opt.opt_expr.eqneq.cmpzero", "$eq", "$ne", cell->type.str());
log_debug("Replacing %s cell `%s' in module `%s' with %s.\n", log_id(cell->type), log_id(cell),
- log_id(module), "$eq" ? "$logic_not" : "$reduce_bool");
+ log_id(module), cell->type == ID($eq) ? "$logic_not" : "$reduce_bool");
cell->type = cell->type == ID($eq) ? ID($logic_not) : ID($reduce_bool);
if (assign_map(cell->getPort(ID::A)).is_fully_zero()) {
cell->setPort(ID::A, cell->getPort(ID::B));
-
bram $__XILINX_RAMB36_SDP
init 1
abits 9
clkpol 2 3
endbram
+# The "min bits" value were taken from:
+# [[CITE]] 7 Series FPGAs Memory Resources User Guide (UG473),
+# v1.14 ed., p 29-30, July, 2019.
+# https://www.xilinx.com/support/documentation/user_guides/ug473_7Series_Memory_Resources.pdf
+
match $__XILINX_RAMB36_SDP
- min bits 4096
+ attribute !ram_style
+ attribute !logic_block
+ min bits 1024
min efficiency 5
shuffle_enable B
make_transp
or_next_if_better
endmatch
+match $__XILINX_RAMB36_SDP
+ attribute ram_style=block ram_block
+ attribute !logic_block
+ shuffle_enable B
+ make_transp
+ or_next_if_better
+endmatch
+
match $__XILINX_RAMB18_SDP
- min bits 4096
+ attribute !ram_style
+ attribute !logic_block
+ min bits 1024
min efficiency 5
shuffle_enable B
make_transp
or_next_if_better
endmatch
+match $__XILINX_RAMB18_SDP
+ attribute ram_style=block ram_block
+ attribute !logic_block
+ shuffle_enable B
+ make_transp
+ or_next_if_better
+endmatch
+
match $__XILINX_RAMB36_TDP
- min bits 4096
+ attribute !ram_style
+ attribute !logic_block
+ min bits 1024
min efficiency 5
shuffle_enable B
make_transp
or_next_if_better
endmatch
+match $__XILINX_RAMB36_TDP
+ attribute ram_style=block ram_block
+ attribute !logic_block
+ shuffle_enable B
+ make_transp
+ or_next_if_better
+endmatch
+
match $__XILINX_RAMB18_TDP
- min bits 4096
+ attribute !ram_style
+ attribute !logic_block
+ min bits 1024
min efficiency 5
shuffle_enable B
make_transp
+ or_next_if_better
+endmatch
+
+match $__XILINX_RAMB18_TDP
+ attribute ram_style=block ram_block
+ attribute !logic_block
+ shuffle_enable B
+ make_transp
endmatch
--- /dev/null
+`default_nettype none
+module sync_ram_sp #(parameter DATA_WIDTH=8, ADDRESS_WIDTH=10)
+ (input wire write_enable, clk,
+ input wire [DATA_WIDTH-1:0] data_in,
+ input wire [ADDRESS_WIDTH-1:0] address_in,
+ output wire [DATA_WIDTH-1:0] data_out);
+
+ localparam WORD = (DATA_WIDTH-1);
+ localparam DEPTH = (2**ADDRESS_WIDTH-1);
+
+ reg [WORD:0] data_out_r;
+ reg [WORD:0] memory [0:DEPTH];
+
+ always @(posedge clk) begin
+ if (write_enable)
+ memory[address_in] <= data_in;
+ data_out_r <= memory[address_in];
+ end
+
+ assign data_out = data_out_r;
+endmodule // sync_ram_sp
+
+
+`default_nettype none
+module sync_ram_sdp #(parameter DATA_WIDTH=8, ADDRESS_WIDTH=10)
+ (input wire clk, write_enable,
+ input wire [DATA_WIDTH-1:0] data_in,
+ input wire [ADDRESS_WIDTH-1:0] address_in_r, address_in_w,
+ output wire [DATA_WIDTH-1:0] data_out);
+
+ localparam WORD = (DATA_WIDTH-1);
+ localparam DEPTH = (2**ADDRESS_WIDTH-1);
+
+ reg [WORD:0] data_out_r;
+ reg [WORD:0] memory [0:DEPTH];
+
+ always @(posedge clk) begin
+ if (write_enable)
+ memory[address_in_w] <= data_in;
+ data_out_r <= memory[address_in_r];
+ end
+
+ assign data_out = data_out_r;
+endmodule // sync_ram_sdp
+
--- /dev/null
+`default_nettype none
+module block_ram #(parameter DATA_WIDTH=4, ADDRESS_WIDTH=10)
+ (input wire write_enable, clk,
+ input wire [DATA_WIDTH-1:0] data_in,
+ input wire [ADDRESS_WIDTH-1:0] address_in,
+ output wire [DATA_WIDTH-1:0] data_out);
+
+ localparam WORD = (DATA_WIDTH-1);
+ localparam DEPTH = (2**ADDRESS_WIDTH-1);
+
+ reg [WORD:0] data_out_r;
+ reg [WORD:0] memory [0:DEPTH];
+
+ always @(posedge clk) begin
+ if (write_enable)
+ memory[address_in] <= data_in;
+ data_out_r <= memory[address_in];
+ end
+
+ assign data_out = data_out_r;
+endmodule // block_ram
+
+`default_nettype none
+module distributed_ram #(parameter DATA_WIDTH=8, ADDRESS_WIDTH=4)
+ (input wire write_enable, clk,
+ input wire [DATA_WIDTH-1:0] data_in,
+ input wire [ADDRESS_WIDTH-1:0] address_in,
+ output wire [DATA_WIDTH-1:0] data_out);
+
+ localparam WORD = (DATA_WIDTH-1);
+ localparam DEPTH = (2**ADDRESS_WIDTH-1);
+
+ reg [WORD:0] data_out_r;
+ reg [WORD:0] memory [0:DEPTH];
+
+ always @(posedge clk) begin
+ if (write_enable)
+ memory[address_in] <= data_in;
+ data_out_r <= memory[address_in];
+ end
+
+ assign data_out = data_out_r;
+endmodule // distributed_ram
+
+`default_nettype none
+module distributed_ram_manual #(parameter DATA_WIDTH=8, ADDRESS_WIDTH=4)
+ (input wire write_enable, clk,
+ input wire [DATA_WIDTH-1:0] data_in,
+ input wire [ADDRESS_WIDTH-1:0] address_in,
+ output wire [DATA_WIDTH-1:0] data_out);
+
+ localparam WORD = (DATA_WIDTH-1);
+ localparam DEPTH = (2**ADDRESS_WIDTH-1);
+
+ reg [WORD:0] data_out_r;
+ (* ram_style = "block" *) reg [WORD:0] memory [0:DEPTH];
+
+ always @(posedge clk) begin
+ if (write_enable)
+ memory[address_in] <= data_in;
+ data_out_r <= memory[address_in];
+ end
+
+ assign data_out = data_out_r;
+endmodule // distributed_ram
+
+`default_nettype none
+module distributed_ram_manual_syn #(parameter DATA_WIDTH=8, ADDRESS_WIDTH=4)
+ (input wire write_enable, clk,
+ input wire [DATA_WIDTH-1:0] data_in,
+ input wire [ADDRESS_WIDTH-1:0] address_in,
+ output wire [DATA_WIDTH-1:0] data_out);
+
+ localparam WORD = (DATA_WIDTH-1);
+ localparam DEPTH = (2**ADDRESS_WIDTH-1);
+
+ reg [WORD:0] data_out_r;
+ (* synthesis, ram_block *) reg [WORD:0] memory [0:DEPTH];
+
+ always @(posedge clk) begin
+ if (write_enable)
+ memory[address_in] <= data_in;
+ data_out_r <= memory[address_in];
+ end
+
+ assign data_out = data_out_r;
+endmodule // distributed_ram
+
--- /dev/null
+# Check that blockram memory without parameters is not modified
+read_verilog ../common/memory_attributes/attributes_test.v
+hierarchy -top block_ram
+synth_xilinx -top block_ram
+cd block_ram # Constrain all select calls below inside the top module
+select -assert-count 1 t:RAMB18E1
+
+# Check that distributed memory without parameters is not modified
+design -reset
+read_verilog ../common/memory_attributes/attributes_test.v
+hierarchy -top distributed_ram
+synth_xilinx -top distributed_ram
+cd distributed_ram # Constrain all select calls below inside the top module
+select -assert-count 8 t:RAM32X1D
+
+# Set ram_style distributed to blockram memory; will be implemented as distributed
+design -reset
+read_verilog ../common/memory_attributes/attributes_test.v
+prep
+setattr -mod -set ram_style "distributed" block_ram
+synth_xilinx -top block_ram
+cd block_ram # Constrain all select calls below inside the top module
+select -assert-count 32 t:RAM128X1D
+
+# Set synthesis, logic_block to blockram memory; will be implemented as distributed
+design -reset
+read_verilog ../common/memory_attributes/attributes_test.v
+prep
+setattr -mod -set logic_block 1 block_ram
+synth_xilinx -top block_ram
+cd block_ram # Constrain all select calls below inside the top module
+select -assert-count 0 t:RAMB18E1
+select -assert-count 32 t:RAM128X1D
+
+# Set ram_style block to a distributed memory; will be implemented as blockram
+design -reset
+read_verilog ../common/memory_attributes/attributes_test.v
+synth_xilinx -top distributed_ram_manual
+cd distributed_ram_manual # Constrain all select calls below inside the top module
+select -assert-count 1 t:RAMB18E1
+
+# Set synthesis, ram_block block to a distributed memory; will be implemented as blockram
+design -reset
+read_verilog ../common/memory_attributes/attributes_test.v
+synth_xilinx -top distributed_ram_manual_syn
+cd distributed_ram_manual_syn # Constrain all select calls below inside the top module
+select -assert-count 1 t:RAMB18E1
--- /dev/null
+### TODO: Not running equivalence checking because BRAM models does not exists
+### currently. Checking instance counts instead.
+# Memory bits <= 18K; Data width <= 36; Address width <= 14: -> RAMB18E1
+read_verilog ../common/blockram.v
+chparam -set ADDRESS_WIDTH 10 -set DATA_WIDTH 1 sync_ram_sdp
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 1 t:RAMB18E1
+
+design -reset
+read_verilog ../common/blockram.v
+chparam -set ADDRESS_WIDTH 8 -set DATA_WIDTH 18 sync_ram_sdp
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 1 t:RAMB18E1
+
+design -reset
+read_verilog ../common/blockram.v
+chparam -set ADDRESS_WIDTH 14 -set DATA_WIDTH 1 sync_ram_sdp
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 1 t:RAMB18E1
+
+design -reset
+read_verilog ../common/blockram.v
+chparam -set ADDRESS_WIDTH 9 -set DATA_WIDTH 36 sync_ram_sdp
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 1 t:RAMB18E1
+
+# Anything memory bits < 1024 -> LUTRAM
+design -reset
+read_verilog ../common/blockram.v
+chparam -set ADDRESS_WIDTH 8 -set DATA_WIDTH 2 sync_ram_sdp
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 0 t:RAMB18E1
+select -assert-count 4 t:RAM128X1D
+
+# More than 18K bits, data width <= 36 (TDP), and address width from 10 to 15b (non-cascaded) -> RAMB36E1
+design -reset
+read_verilog ../common/blockram.v
+chparam -set ADDRESS_WIDTH 10 -set DATA_WIDTH 36 sync_ram_sdp
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 1 t:RAMB36E1
+
+
+### With parameters
+
+design -reset
+read_verilog ../common/blockram.v
+hierarchy -top sync_ram_sdp -chparam ADDRESS_WIDTH 10 -chparam DATA_WIDTH 1
+setattr -set ram_style "block" m:memory
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 1 t:RAMB18E1
+
+design -reset
+read_verilog ../common/blockram.v
+hierarchy -top sync_ram_sdp -chparam ADDRESS_WIDTH 10 -chparam DATA_WIDTH 1
+setattr -set ram_block 1 m:memory
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 1 t:RAMB18E1
+
+design -reset
+read_verilog ../common/blockram.v
+hierarchy -top sync_ram_sdp -chparam ADDRESS_WIDTH 10 -chparam DATA_WIDTH 1
+setattr -set ram_style "dont_infer_a_ram_pretty_please" m:memory
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 0 t:RAMB18E1
+
+design -reset
+read_verilog ../common/blockram.v
+hierarchy -top sync_ram_sdp -chparam ADDRESS_WIDTH 10 -chparam DATA_WIDTH 1
+setattr -set logic_block 1 m:memory
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 0 t:RAMB18E1
+
+design -reset
+read_verilog ../common/blockram.v
+hierarchy -top sync_ram_sdp -chparam ADDRESS_WIDTH 8 -chparam DATA_WIDTH 1
+setattr -set ram_style "block" m:memory
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 1 t:RAMB18E1
+
+design -reset
+read_verilog ../common/blockram.v
+hierarchy -top sync_ram_sdp -chparam ADDRESS_WIDTH 8 -chparam DATA_WIDTH 1
+setattr -set ram_block 1 m:memory
+synth_xilinx -top sync_ram_sdp
+cd sync_ram_sdp
+select -assert-count 1 t:RAMB18E1