lm32_debug.v

changeset 24
c336e674a37e
parent 23
252df75c8f67
child 25
7422134cbfea
     1.1 --- a/lm32_debug.v	Sun Mar 06 21:17:31 2011 +0000
     1.2 +++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.3 @@ -1,348 +0,0 @@
     1.4 -// =============================================================================
     1.5 -//                           COPYRIGHT NOTICE
     1.6 -// Copyright 2006 (c) Lattice Semiconductor Corporation
     1.7 -// ALL RIGHTS RESERVED
     1.8 -// This confidential and proprietary software may be used only as authorised by
     1.9 -// a licensing agreement from Lattice Semiconductor Corporation.
    1.10 -// The entire notice above must be reproduced on all authorized copies and
    1.11 -// copies may only be made to the extent permitted by a licensing agreement from
    1.12 -// Lattice Semiconductor Corporation.
    1.13 -//
    1.14 -// Lattice Semiconductor Corporation        TEL : 1-800-Lattice (USA and Canada)
    1.15 -// 5555 NE Moore Court                            408-826-6000 (other locations)
    1.16 -// Hillsboro, OR 97124                     web  : http://www.latticesemi.com/
    1.17 -// U.S.A                                   email: techsupport@latticesemi.com
    1.18 -// =============================================================================/
    1.19 -//                         FILE DETAILS
    1.20 -// Project          : LatticeMico32
    1.21 -// File             : lm32_debug.v
    1.22 -// Title            : Hardware debug registers and associated logic.
    1.23 -// Dependencies     : lm32_include.v
    1.24 -// Version          : 6.1.17
    1.25 -//                  : Initial Release
    1.26 -// Version          : 7.0SP2, 3.0
    1.27 -//                  : No Change
    1.28 -// Version          : 3.1
    1.29 -//                  : No Change
    1.30 -// Version          : 3.2
    1.31 -//                  : Fixed simulation bug which flares up when number of 
    1.32 -//                  : watchpoints is zero.
    1.33 -// =============================================================================
    1.34 -
    1.35 -`include "lm32_include.v"
    1.36 -
    1.37 -`ifdef CFG_DEBUG_ENABLED
    1.38 -
    1.39 -// States for single-step FSM
    1.40 -`define LM32_DEBUG_SS_STATE_RNG                 2:0
    1.41 -`define LM32_DEBUG_SS_STATE_IDLE                3'b000
    1.42 -`define LM32_DEBUG_SS_STATE_WAIT_FOR_RET        3'b001
    1.43 -`define LM32_DEBUG_SS_STATE_EXECUTE_ONE_INSN    3'b010
    1.44 -`define LM32_DEBUG_SS_STATE_RAISE_BREAKPOINT    3'b011
    1.45 -`define LM32_DEBUG_SS_STATE_RESTART             3'b100
    1.46 -
    1.47 -/////////////////////////////////////////////////////
    1.48 -// Module interface
    1.49 -/////////////////////////////////////////////////////
    1.50 -
    1.51 -module lm32_debug (
    1.52 -    // ----- Inputs -------
    1.53 -    clk_i, 
    1.54 -    rst_i,
    1.55 -    pc_x,
    1.56 -    load_x,
    1.57 -    store_x,
    1.58 -    load_store_address_x,
    1.59 -    csr_write_enable_x,
    1.60 -    csr_write_data,
    1.61 -    csr_x,
    1.62 -`ifdef CFG_HW_DEBUG_ENABLED
    1.63 -    jtag_csr_write_enable,
    1.64 -    jtag_csr_write_data,
    1.65 -    jtag_csr,
    1.66 -`endif
    1.67 -`ifdef LM32_SINGLE_STEP_ENABLED
    1.68 -    eret_q_x,
    1.69 -    bret_q_x,
    1.70 -    stall_x,
    1.71 -    exception_x,
    1.72 -    q_x,
    1.73 -`ifdef CFG_DCACHE_ENABLED
    1.74 -    dcache_refill_request,
    1.75 -`endif
    1.76 -`endif
    1.77 -    // ----- Outputs -------
    1.78 -`ifdef LM32_SINGLE_STEP_ENABLED
    1.79 -    dc_ss,
    1.80 -`endif
    1.81 -    dc_re,
    1.82 -    bp_match,
    1.83 -    wp_match
    1.84 -    );
    1.85 -    
    1.86 -/////////////////////////////////////////////////////
    1.87 -// Parameters
    1.88 -/////////////////////////////////////////////////////
    1.89 -
    1.90 -parameter breakpoints = 0;                      // Number of breakpoint CSRs
    1.91 -parameter watchpoints = 0;                      // Number of watchpoint CSRs
    1.92 -
    1.93 -/////////////////////////////////////////////////////
    1.94 -// Inputs
    1.95 -/////////////////////////////////////////////////////
    1.96 -
    1.97 -input clk_i;                                    // Clock
    1.98 -input rst_i;                                    // Reset
    1.99 -
   1.100 -input [`LM32_PC_RNG] pc_x;                      // X stage PC
   1.101 -input load_x;                                   // Load instruction in X stage
   1.102 -input store_x;                                  // Store instruction in X stage
   1.103 -input [`LM32_WORD_RNG] load_store_address_x;    // Load or store effective address
   1.104 -input csr_write_enable_x;                       // wcsr instruction in X stage
   1.105 -input [`LM32_WORD_RNG] csr_write_data;          // Data to write to CSR
   1.106 -input [`LM32_CSR_RNG] csr_x;                    // Which CSR to write
   1.107 -`ifdef CFG_HW_DEBUG_ENABLED
   1.108 -input jtag_csr_write_enable;                    // JTAG interface CSR write enable
   1.109 -input [`LM32_WORD_RNG] jtag_csr_write_data;     // Data to write to CSR
   1.110 -input [`LM32_CSR_RNG] jtag_csr;                 // Which CSR to write
   1.111 -`endif
   1.112 -`ifdef LM32_SINGLE_STEP_ENABLED
   1.113 -input eret_q_x;                                 // eret instruction in X stage
   1.114 -input bret_q_x;                                 // bret instruction in X stage
   1.115 -input stall_x;                                  // Instruction in X stage is stalled
   1.116 -input exception_x;                              // An exception has occured in X stage 
   1.117 -input q_x;                                      // Indicates the instruction in the X stage is qualified
   1.118 -`ifdef CFG_DCACHE_ENABLED
   1.119 -input dcache_refill_request;                    // Indicates data cache wants to be refilled 
   1.120 -`endif
   1.121 -`endif
   1.122 -
   1.123 -/////////////////////////////////////////////////////
   1.124 -// Outputs
   1.125 -/////////////////////////////////////////////////////
   1.126 -
   1.127 -`ifdef LM32_SINGLE_STEP_ENABLED
   1.128 -output dc_ss;                                   // Single-step enable
   1.129 -reg    dc_ss;
   1.130 -`endif
   1.131 -output dc_re;                                   // Remap exceptions
   1.132 -reg    dc_re;
   1.133 -output bp_match;                                // Indicates a breakpoint has matched
   1.134 -wire   bp_match;        
   1.135 -output wp_match;                                // Indicates a watchpoint has matched
   1.136 -wire   wp_match;
   1.137 -
   1.138 -/////////////////////////////////////////////////////
   1.139 -// Internal nets and registers 
   1.140 -/////////////////////////////////////////////////////
   1.141 -
   1.142 -genvar i;                                       // Loop index for generate statements
   1.143 -
   1.144 -// Debug CSRs
   1.145 -
   1.146 -reg [`LM32_PC_RNG] bp_a[0:breakpoints-1];       // Instruction breakpoint address
   1.147 -reg bp_e[0:breakpoints-1];                      // Instruction breakpoint enable
   1.148 -wire [0:breakpoints-1]bp_match_n;               // Indicates if a h/w instruction breakpoint matched
   1.149 -
   1.150 -reg [`LM32_WPC_C_RNG] wpc_c[0:watchpoints-1];   // Watchpoint enable
   1.151 -reg [`LM32_WORD_RNG] wp[0:watchpoints-1];       // Watchpoint address
   1.152 -wire [0:watchpoints]wp_match_n;               // Indicates if a h/w data watchpoint matched
   1.153 -
   1.154 -wire debug_csr_write_enable;                    // Debug CSR write enable (from either a wcsr instruction of external debugger)
   1.155 -wire [`LM32_WORD_RNG] debug_csr_write_data;     // Data to write to debug CSR
   1.156 -wire [`LM32_CSR_RNG] debug_csr;                 // Debug CSR to write to
   1.157 -
   1.158 -`ifdef LM32_SINGLE_STEP_ENABLED
   1.159 -// FIXME: Declaring this as a reg causes ModelSim 6.1.15b to crash, so use integer for now
   1.160 -//reg [`LM32_DEBUG_SS_STATE_RNG] state;           // State of single-step FSM
   1.161 -integer state;                                  // State of single-step FSM
   1.162 -`endif
   1.163 -
   1.164 -/////////////////////////////////////////////////////
   1.165 -// Functions
   1.166 -/////////////////////////////////////////////////////
   1.167 -
   1.168 -`include "lm32_functions.v"
   1.169 -
   1.170 -/////////////////////////////////////////////////////
   1.171 -// Combinational Logic
   1.172 -/////////////////////////////////////////////////////
   1.173 -
   1.174 -// Check for breakpoints
   1.175 -generate
   1.176 -    for (i = 0; i < breakpoints; i = i + 1)
   1.177 -    begin : bp_comb
   1.178 -assign bp_match_n[i] = ((bp_a[i] == pc_x) && (bp_e[i] == `TRUE));
   1.179 -    end
   1.180 -endgenerate
   1.181 -generate 
   1.182 -`ifdef LM32_SINGLE_STEP_ENABLED
   1.183 -    if (breakpoints > 0) 
   1.184 -assign bp_match = (|bp_match_n) || (state == `LM32_DEBUG_SS_STATE_RAISE_BREAKPOINT);
   1.185 -    else
   1.186 -assign bp_match = state == `LM32_DEBUG_SS_STATE_RAISE_BREAKPOINT;
   1.187 -`else
   1.188 -    if (breakpoints > 0) 
   1.189 -assign bp_match = |bp_match_n;
   1.190 -    else
   1.191 -assign bp_match = `FALSE;
   1.192 -`endif
   1.193 -endgenerate    
   1.194 -               
   1.195 -// Check for watchpoints
   1.196 -generate 
   1.197 -    for (i = 0; i < watchpoints; i = i + 1)
   1.198 -    begin : wp_comb
   1.199 -assign wp_match_n[i] = (wp[i] == load_store_address_x) && ((load_x & wpc_c[i][0]) | (store_x & wpc_c[i][1]));
   1.200 -    end               
   1.201 -endgenerate
   1.202 -generate
   1.203 -    if (watchpoints > 0) 
   1.204 -assign wp_match = |wp_match_n;                
   1.205 -    else
   1.206 -assign wp_match = `FALSE;
   1.207 -endgenerate
   1.208 -                
   1.209 -`ifdef CFG_HW_DEBUG_ENABLED                
   1.210 -// Multiplex between wcsr instruction writes and debugger writes to the debug CSRs
   1.211 -assign debug_csr_write_enable = (csr_write_enable_x == `TRUE) || (jtag_csr_write_enable == `TRUE);
   1.212 -assign debug_csr_write_data = jtag_csr_write_enable == `TRUE ? jtag_csr_write_data : csr_write_data;
   1.213 -assign debug_csr = jtag_csr_write_enable == `TRUE ? jtag_csr : csr_x;
   1.214 -`else
   1.215 -assign debug_csr_write_enable = csr_write_enable_x;
   1.216 -assign debug_csr_write_data = csr_write_data;
   1.217 -assign debug_csr = csr_x;
   1.218 -`endif
   1.219 -
   1.220 -/////////////////////////////////////////////////////
   1.221 -// Sequential Logic
   1.222 -/////////////////////////////////////////////////////
   1.223 -
   1.224 -// Breakpoint address and enable CSRs
   1.225 -generate
   1.226 -    for (i = 0; i < breakpoints; i = i + 1)
   1.227 -    begin : bp_seq
   1.228 -always @(posedge clk_i `CFG_RESET_SENSITIVITY)
   1.229 -begin
   1.230 -    if (rst_i == `TRUE)
   1.231 -    begin
   1.232 -        bp_a[i] <= {`LM32_PC_WIDTH{1'bx}};
   1.233 -        bp_e[i] <= `FALSE;
   1.234 -    end
   1.235 -    else
   1.236 -    begin
   1.237 -        if ((debug_csr_write_enable == `TRUE) && (debug_csr == `LM32_CSR_BP0 + i))
   1.238 -        begin
   1.239 -            bp_a[i] <= debug_csr_write_data[`LM32_PC_RNG];
   1.240 -            bp_e[i] <= debug_csr_write_data[0];
   1.241 -        end
   1.242 -    end
   1.243 -end    
   1.244 -    end
   1.245 -endgenerate
   1.246 -
   1.247 -// Watchpoint address and control flags CSRs
   1.248 -generate
   1.249 -    for (i = 0; i < watchpoints; i = i + 1)
   1.250 -    begin : wp_seq
   1.251 -always @(posedge clk_i `CFG_RESET_SENSITIVITY)
   1.252 -begin
   1.253 -    if (rst_i == `TRUE)
   1.254 -    begin
   1.255 -        wp[i] <= {`LM32_WORD_WIDTH{1'bx}};
   1.256 -        wpc_c[i] <= `LM32_WPC_C_DISABLED;
   1.257 -    end
   1.258 -    else
   1.259 -    begin
   1.260 -        if (debug_csr_write_enable == `TRUE)
   1.261 -        begin
   1.262 -            if (debug_csr == `LM32_CSR_DC)
   1.263 -                wpc_c[i] <= debug_csr_write_data[3+i*2:2+i*2];
   1.264 -            if (debug_csr == `LM32_CSR_WP0 + i)
   1.265 -                wp[i] <= debug_csr_write_data;
   1.266 -        end
   1.267 -    end  
   1.268 -end
   1.269 -    end
   1.270 -endgenerate
   1.271 -
   1.272 -// Remap exceptions control bit
   1.273 -always @(posedge clk_i `CFG_RESET_SENSITIVITY)
   1.274 -begin
   1.275 -    if (rst_i == `TRUE)
   1.276 -        dc_re <= `FALSE;
   1.277 -    else
   1.278 -    begin
   1.279 -        if ((debug_csr_write_enable == `TRUE) && (debug_csr == `LM32_CSR_DC))
   1.280 -            dc_re <= debug_csr_write_data[1];
   1.281 -    end
   1.282 -end    
   1.283 -
   1.284 -`ifdef LM32_SINGLE_STEP_ENABLED
   1.285 -// Single-step control flag
   1.286 -always @(posedge clk_i `CFG_RESET_SENSITIVITY)
   1.287 -begin
   1.288 -    if (rst_i == `TRUE)
   1.289 -    begin
   1.290 -        state <= `LM32_DEBUG_SS_STATE_IDLE;
   1.291 -        dc_ss <= `FALSE;
   1.292 -    end
   1.293 -    else
   1.294 -    begin
   1.295 -        if ((debug_csr_write_enable == `TRUE) && (debug_csr == `LM32_CSR_DC))
   1.296 -        begin
   1.297 -            dc_ss <= debug_csr_write_data[0];
   1.298 -            if (debug_csr_write_data[0] == `FALSE) 
   1.299 -                state <= `LM32_DEBUG_SS_STATE_IDLE;
   1.300 -            else 
   1.301 -                state <= `LM32_DEBUG_SS_STATE_WAIT_FOR_RET;
   1.302 -        end
   1.303 -        case (state)
   1.304 -        `LM32_DEBUG_SS_STATE_WAIT_FOR_RET:
   1.305 -        begin
   1.306 -            // Wait for eret or bret instruction to be executed
   1.307 -            if (   (   (eret_q_x == `TRUE)
   1.308 -                    || (bret_q_x == `TRUE)
   1.309 -                    )
   1.310 -                && (stall_x == `FALSE)
   1.311 -               )
   1.312 -                state <= `LM32_DEBUG_SS_STATE_EXECUTE_ONE_INSN; 
   1.313 -        end
   1.314 -        `LM32_DEBUG_SS_STATE_EXECUTE_ONE_INSN:
   1.315 -        begin
   1.316 -            // Wait for an instruction to be executed
   1.317 -            if ((q_x == `TRUE) && (stall_x == `FALSE))
   1.318 -                state <= `LM32_DEBUG_SS_STATE_RAISE_BREAKPOINT;
   1.319 -        end
   1.320 -        `LM32_DEBUG_SS_STATE_RAISE_BREAKPOINT:
   1.321 -        begin
   1.322 -            // Wait for exception to be raised
   1.323 -`ifdef CFG_DCACHE_ENABLED
   1.324 -            if (dcache_refill_request == `TRUE)
   1.325 -                state <= `LM32_DEBUG_SS_STATE_EXECUTE_ONE_INSN;
   1.326 -            else 
   1.327 -`endif
   1.328 -                 if ((exception_x == `TRUE) && (q_x == `TRUE) && (stall_x == `FALSE))
   1.329 -            begin
   1.330 -                dc_ss <= `FALSE;
   1.331 -                state <= `LM32_DEBUG_SS_STATE_RESTART;
   1.332 -            end
   1.333 -        end
   1.334 -        `LM32_DEBUG_SS_STATE_RESTART:
   1.335 -        begin
   1.336 -            // Watch to see if stepped instruction is restarted due to a cache miss
   1.337 -`ifdef CFG_DCACHE_ENABLED
   1.338 -            if (dcache_refill_request == `TRUE)
   1.339 -                state <= `LM32_DEBUG_SS_STATE_EXECUTE_ONE_INSN;
   1.340 -            else 
   1.341 -`endif
   1.342 -                state <= `LM32_DEBUG_SS_STATE_IDLE;
   1.343 -        end
   1.344 -        endcase
   1.345 -    end
   1.346 -end
   1.347 -`endif
   1.348 -
   1.349 -endmodule
   1.350 -
   1.351 -`endif