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Diffstat (limited to 'src/systemc/tests/systemc/misc/sim_tests/simple_cpu/simple_cpu.cpp')
-rw-r--r--src/systemc/tests/systemc/misc/sim_tests/simple_cpu/simple_cpu.cpp254
1 files changed, 254 insertions, 0 deletions
diff --git a/src/systemc/tests/systemc/misc/sim_tests/simple_cpu/simple_cpu.cpp b/src/systemc/tests/systemc/misc/sim_tests/simple_cpu/simple_cpu.cpp
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index 000000000..5e7b0cc4a
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+++ b/src/systemc/tests/systemc/misc/sim_tests/simple_cpu/simple_cpu.cpp
@@ -0,0 +1,254 @@
+/*****************************************************************************
+
+ Licensed to Accellera Systems Initiative Inc. (Accellera) under one or
+ more contributor license agreements. See the NOTICE file distributed
+ with this work for additional information regarding copyright ownership.
+ Accellera licenses this file to you under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with the
+ License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ implied. See the License for the specific language governing
+ permissions and limitations under the License.
+
+ *****************************************************************************/
+
+/*****************************************************************************
+
+ simple_cpu.cpp --
+
+ Original Author: Martin Janssen, Synopsys, Inc., 2002-02-15
+
+ *****************************************************************************/
+
+/*****************************************************************************
+
+ MODIFICATION LOG - modifiers, enter your name, affiliation, date and
+ changes you are making here.
+
+ Name, Affiliation, Date:
+ Description of Modification:
+
+ *****************************************************************************/
+
+#include "systemc.h"
+
+#define READ 0
+#define WRITE 1
+
+SC_MODULE( exec_decode )
+{
+ SC_HAS_PROCESS( exec_decode );
+
+ sc_in<unsigned> instruction;
+ sc_signal<unsigned>& program_counter;
+
+ unsigned pc; // Program counter
+ unsigned cpu_reg[32]; // Cpu registers
+
+ unsigned *data_mem; // The data memory
+
+ exec_decode( sc_module_name NAME,
+ sc_signal<unsigned>& INSTRUCTION,
+ sc_signal<unsigned>& PROGRAM_COUNTER )
+ : program_counter(PROGRAM_COUNTER)
+ {
+ instruction(INSTRUCTION);
+ SC_METHOD( entry );
+ // sensitive only to the clock
+ sensitive << instruction;
+
+ pc = 0x000000; // Power up reset value
+ for (int i =0; i<32; i++) cpu_reg[i] = 0;
+
+ // Initialize the data memory from file datamem
+ FILE *fp = fopen("simple_cpu/datamem", "r");
+ if (fp == (FILE *) 0) return; // No data mem file to read
+ // First field in this file is the size of data memory desired
+ int size;
+ fscanf(fp, "%d", &size);
+ data_mem = new unsigned[size];
+ if (data_mem == (unsigned *) 0) {
+ printf("Not enough memory left\n");
+ return;
+ }
+ unsigned mem_word;
+ size = 0;
+ while (fscanf(fp, "%x", &mem_word) != EOF) {
+ data_mem[size++] = mem_word;
+ }
+
+ // Start off simulation by writing program_counter
+ program_counter.write(pc);
+ }
+
+ // Functionality
+ void entry();
+};
+
+void
+exec_decode::entry()
+{
+ unsigned instr;
+ unsigned opcode;
+ unsigned regnum1, regnum2, regnum3;
+ unsigned addr;
+
+ int i;
+
+ instr = instruction.read();
+ opcode = (instr & 0xe0000000) >> 29; // Extract opcode
+ switch(opcode) {
+ case 0x0: // Halt
+ printf("CPU Halted\n");
+ printf("\tPC = 0x%x\n", pc);
+ for (i = 0; i < 32; i++)
+ printf("\tR[%d] = %x\n", i, cpu_reg[i]);
+ // Don't write pc and execution will stop
+ break;
+ case 0x1: // Store
+ regnum1 = (instr & 0x1f000000) >> 24; // Extract register number
+ addr = (instr & 0x00ffffff); // Extract address
+ printf("Store: Memory[0x%x] = R[%d]\n", addr, regnum1);
+ data_mem[addr] = cpu_reg[regnum1];
+ pc = pc + 1;
+ program_counter.write(pc);
+ break;
+ case 0x2: // Load
+ regnum1 = (instr & 0x1f000000) >> 24; // Extract register number
+ addr = (instr & 0x00ffffff); // Extract address
+ printf("Load: R[%d] = Memory[0x%x]\n", regnum1, addr);
+ cpu_reg[regnum1] = data_mem[addr];
+ pc = pc + 1;
+ program_counter.write(pc);
+ break;
+ case 0x3: // Add
+ regnum1 = (instr & 0x1f000000) >> 24; // Extract register number
+ regnum2 = (instr & 0x00f80000) >> 19; // Extract register number
+ regnum3 = (instr & 0x0007c000) >> 14; // Extract register number
+ printf("R[%d] = R[%d] + R[%d]\n", regnum3, regnum1, regnum2);
+ cpu_reg[regnum3] = cpu_reg[regnum1] + cpu_reg[regnum2];
+ pc = pc + 1;
+ program_counter.write(pc);
+ break;
+ case 0x4: // Subtract
+ regnum1 = (instr & 0x1f000000) >> 24; // Extract register number
+ regnum2 = (instr & 0x00f80000) >> 19; // Extract register number
+ regnum3 = (instr & 0x0007c000) >> 14; // Extract register number
+ printf("R[%d] = R[%d] - R[%d]\n", regnum3, regnum1, regnum2);
+ cpu_reg[regnum3] = cpu_reg[regnum1] - cpu_reg[regnum2];
+ pc = pc + 1;
+ program_counter.write(pc);
+ break;
+ case 0x5: // Multiply
+ regnum1 = (instr & 0x1f000000) >> 24; // Extract register number
+ regnum2 = (instr & 0x00f80000) >> 19; // Extract register number
+ regnum3 = (instr & 0x0007c000) >> 14; // Extract register number
+ printf("R[%d] = R[%d] * R[%d]\n", regnum3, regnum1, regnum2);
+ cpu_reg[regnum3] = cpu_reg[regnum1] * cpu_reg[regnum2];
+ pc = pc + 1;
+ program_counter.write(pc);
+ break;
+ case 0x6: // Divide
+ regnum1 = (instr & 0x1f000000) >> 24; // Extract register number
+ regnum2 = (instr & 0x00f80000) >> 19; // Extract register number
+ regnum3 = (instr & 0x0007c000) >> 14; // Extract register number
+ printf("R[%d] = R[%d] / R[%d]\n", regnum3, regnum1, regnum2);
+ if (cpu_reg[regnum2] == 0) {
+ printf("Division exception - divide by zero\n");
+ }
+ else {
+ cpu_reg[regnum3] = cpu_reg[regnum1] / cpu_reg[regnum2];
+ }
+ pc = pc + 1;
+ program_counter.write(pc);
+ break;
+ case 0x7: // JNZ
+ regnum1 = (instr & 0x1f000000) >> 24; // Extract register number
+ addr = (instr & 0x00ffffff); // Extract address
+ printf("JNZ R[%d] 0x%x\n", regnum1, addr);
+ if (cpu_reg[regnum1] == 0x0)
+ pc = pc + 1;
+ else
+ pc = addr;
+ program_counter.write(pc);
+ break;
+ default: // Bad opcode
+ printf("Bad opcode 0x%x\n", opcode);
+ pc = pc + 1;
+ program_counter.write(pc);
+ break;
+ }
+}
+
+
+SC_MODULE( fetch )
+{
+ SC_HAS_PROCESS( fetch );
+
+ sc_in<unsigned> program_counter;
+ sc_signal<unsigned>& instruction;
+
+ unsigned *prog_mem; // The program memory
+
+ fetch( sc_module_name NAME,
+ sc_signal<unsigned>& PROGRAM_COUNTER,
+ sc_signal<unsigned>& INSTRUCTION )
+ : instruction(INSTRUCTION)
+ {
+ program_counter(PROGRAM_COUNTER);
+ SC_METHOD( entry );
+ sensitive << program_counter;
+
+ // Initialize the program memory from file progmem
+ FILE *fp = fopen("simple_cpu/progmem", "r");
+ if (fp == (FILE *) 0) return; // No prog mem file to read
+ // First field in this file is the size of program memory desired
+ int size;
+ fscanf(fp, "%d", &size);
+ prog_mem = new unsigned[size];
+ if (prog_mem == (unsigned *) 0) {
+ printf("Not enough memory left\n");
+ return;
+ }
+ unsigned mem_word;
+ size = 0;
+ while (fscanf(fp, "%x", &mem_word) != EOF) {
+ prog_mem[size++] = mem_word;
+ }
+ instruction.write(0);
+ }
+
+ // Functionality
+ void entry();
+};
+
+void fetch::entry()
+{
+ unsigned pc, instr;
+ pc = program_counter.read();
+ instr = prog_mem[pc];
+ instruction.write(instr);
+}
+
+int
+sc_main(int ac, char *av[])
+{
+ sc_signal<unsigned> pc;
+ sc_signal<unsigned> instr;
+
+ exec_decode ED("ED", instr, pc);
+ fetch F("F", pc, instr);
+
+ // instead of a testbench routine, we include the testbench here
+ sc_start(1, SC_NS);
+ sc_start( 10, SC_NS );
+
+ fflush( stdout );
+
+ return 0;
+}
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