[FPGA-Bitstream] Added an option to ``write_fabric_bitstream`` command to enable outputting don't care bits in bitstream files

openfpga/src/base/openfpga_bitstream.cpp

@@ -94,6 +94,7 @@ int write_fabric_bitstream(const OpenfpgaContext& openfpga_ctx,
   CommandOptionId opt_file = cmd.option("file");
   CommandOptionId opt_file_format = cmd.option("format");
   CommandOptionId opt_fast_config = cmd.option("fast_configuration");
+  CommandOptionId opt_keep_dont_care_bits = cmd.option("keep_dont_care_bits");
 
   /* Write fabric bitstream if required */
   int status = CMD_EXEC_SUCCESS;
@@ -125,6 +126,7 @@ int write_fabric_bitstream(const OpenfpgaContext& openfpga_ctx,
                                                  openfpga_ctx.fabric_global_port_info(),
                                                  cmd_context.option_value(cmd, opt_file),
                                                  cmd_context.option_enable(cmd, opt_fast_config),
+                                                 cmd_context.option_enable(cmd, opt_keep_dont_care_bits),
                                                  cmd_context.option_enable(cmd, opt_verbose));
   }
   

openfpga/src/base/openfpga_bitstream_command.cpp

@@ -154,6 +154,9 @@ ShellCommandId add_openfpga_write_fabric_bitstream_command(openfpga::Shell<Openf
   /* Add an option '--fast_configuration' */
   shell_cmd.add_option("fast_configuration", false, "Reduce the size of bitstream to be downloaded");
 
+  /* Add an option '--keep_dont_care_bit' */
+  shell_cmd.add_option("keep_dont_care_bit", false, "Keep don't care bits in bitstream file; If not enabled, don't care bits are converted to logic '0' or '1'");
+
   /* Add an option '--verbose' */
   shell_cmd.add_option("verbose", false, "Enable verbose output");
 

openfpga/src/fpga_bitstream/write_text_fabric_bitstream.cpp

@@ -12,6 +12,7 @@
 #include "vtr_time.h"
 
 /* Headers from openfpgautil library */
+#include "openfpga_decode.h"
 #include "openfpga_digest.h"
 #include "openfpga_version.h"
 
@@ -192,10 +193,15 @@ static
 int write_memory_bank_flatten_fabric_bitstream_to_text_file(std::fstream& fp,
                                                             const bool& fast_configuration,
                                                             const bool& bit_value_to_skip,
-                                                            const FabricBitstream& fabric_bitstream) {
+                                                            const FabricBitstream& fabric_bitstream,
+                                                            const bool& keep_dont_care_bits) {
   int status = 0;
 
-  MemoryBankFlattenFabricBitstream fabric_bits = build_memory_bank_flatten_fabric_bitstream(fabric_bitstream, fast_configuration, bit_value_to_skip, 'x');
+  char dont_care_bit = '0';
+  if (keep_dont_care_bits) {
+    dont_care_bit = DONT_CARE_CHAR; 
+  }
+  MemoryBankFlattenFabricBitstream fabric_bits = build_memory_bank_flatten_fabric_bitstream(fabric_bitstream, fast_configuration, bit_value_to_skip, dont_care_bit);
 
   /* The address sizes and data input sizes are the same across any element, 
    * just get it from the 1st element to save runtime
@@ -237,10 +243,15 @@ static
 int write_memory_bank_shift_register_fabric_bitstream_to_text_file(std::fstream& fp,
                                                                    const bool& fast_configuration,
                                                                    const bool& bit_value_to_skip,
-                                                                   const FabricBitstream& fabric_bitstream) {
+                                                                   const FabricBitstream& fabric_bitstream,
+                                                                   const bool& keep_dont_care_bits) {
   int status = 0;
 
-  MemoryBankShiftRegisterFabricBitstream fabric_bits = build_memory_bank_shift_register_fabric_bitstream(fabric_bitstream, fast_configuration, bit_value_to_skip, 'x');
+  char dont_care_bit = '0';
+  if (keep_dont_care_bits) {
+    dont_care_bit = DONT_CARE_CHAR; 
+  }
+  MemoryBankShiftRegisterFabricBitstream fabric_bits = build_memory_bank_shift_register_fabric_bitstream(fabric_bitstream, fast_configuration, bit_value_to_skip, dont_care_bit);
 
   /* Output information about how to intepret the bitstream */
   fp << "// Bitstream word count: " << fabric_bits.num_words() << std::endl;
@@ -356,6 +367,7 @@ int write_fabric_bitstream_to_text_file(const BitstreamManager& bitstream_manage
                                         const FabricGlobalPortInfo& global_ports,
                                         const std::string& fname,
                                         const bool& fast_configuration,
+                                        const bool& keep_dont_care_bits,
                                         const bool& verbose) {
   /* Ensure that we have a valid file name */
   if (true == fname.empty()) {
@@ -419,13 +431,15 @@ int write_fabric_bitstream_to_text_file(const BitstreamManager& bitstream_manage
       status = write_memory_bank_flatten_fabric_bitstream_to_text_file(fp,
                                                                        apply_fast_configuration,
                                                                        bit_value_to_skip,
-                                                                       fabric_bitstream);
+                                                                       fabric_bitstream,
+                                                                       keep_dont_care_bits);
     } else {
       VTR_ASSERT(BLWL_PROTOCOL_SHIFT_REGISTER == config_protocol.bl_protocol_type());
       status = write_memory_bank_shift_register_fabric_bitstream_to_text_file(fp,
                                                                               apply_fast_configuration,
                                                                               bit_value_to_skip,
-                                                                              fabric_bitstream);
+                                                                              fabric_bitstream,
+                                                                              keep_dont_care_bits);
     }
     break;
   } 

openfpga/src/fpga_bitstream/write_text_fabric_bitstream.h

@@ -24,6 +24,7 @@ int write_fabric_bitstream_to_text_file(const BitstreamManager& bitstream_manage
                                         const FabricGlobalPortInfo& global_ports,
                                         const std::string& fname,
                                         const bool& fast_configuration,
+                                        const bool& keep_dont_care_bits,
                                         const bool& verbose);
 
 } /* end namespace openfpga */