1 //----------------------------------------------------------------------------
2 // Copyright (C) 2001 Authors
4 // This source file may be used and distributed without restriction provided
5 // that this copyright statement is not removed from the file and that any
6 // derivative work contains the original copyright notice and the associated
9 // This source file is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU Lesser General Public License as published
11 // by the Free Software Foundation; either version 2.1 of the License, or
12 // (at your option) any later version.
14 // This source is distributed in the hope that it will be useful, but WITHOUT
15 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17 // License for more details.
19 // You should have received a copy of the GNU Lesser General Public License
20 // along with this source; if not, write to the Free Software Foundation,
21 // Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 //----------------------------------------------------------------------------
25 // *File Name: omsp_dbg_hwbrk.v
27 // *Module Description:
28 // Hardware Breakpoint / Watchpoint module
31 // - Olivier Girard, olgirard@gmail.com
33 //----------------------------------------------------------------------------
35 // $LastChangedBy: olivier.girard $
36 // $LastChangedDate: 2010-02-01 23:56:03 +0100 (Mon, 01 Feb 2010) $
37 //----------------------------------------------------------------------------
38 `include "timescale.v"
39 `include "openMSP430_defines.v"
41 module omsp_dbg_hwbrk (
44 brk_halt, // Hardware breakpoint command
45 brk_pnd, // Hardware break/watch-point pending
46 brk_dout, // Hardware break/watch-point register data input
49 brk_reg_rd, // Hardware break/watch-point register read select
50 brk_reg_wr, // Hardware break/watch-point register write select
51 dbg_din, // Debug register data input
52 eu_mab, // Execution-Unit Memory address bus
53 eu_mb_en, // Execution-Unit Memory bus enable
54 eu_mb_wr, // Execution-Unit Memory bus write transfer
55 eu_mdb_in, // Memory data bus input
56 eu_mdb_out, // Memory data bus output
57 exec_done, // Execution completed
58 fe_mb_en, // Frontend Memory bus enable
59 mclk, // Main system clock
60 pc, // Program counter
66 output brk_halt; // Hardware breakpoint command
67 output brk_pnd; // Hardware break/watch-point pending
68 output [15:0] brk_dout; // Hardware break/watch-point register data input
72 input [3:0] brk_reg_rd; // Hardware break/watch-point register read select
73 input [3:0] brk_reg_wr; // Hardware break/watch-point register write select
74 input [15:0] dbg_din; // Debug register data input
75 input [15:0] eu_mab; // Execution-Unit Memory address bus
76 input eu_mb_en; // Execution-Unit Memory bus enable
77 input [1:0] eu_mb_wr; // Execution-Unit Memory bus write transfer
78 input [15:0] eu_mdb_in; // Memory data bus input
79 input [15:0] eu_mdb_out; // Memory data bus output
80 input exec_done; // Execution completed
81 input fe_mb_en; // Frontend Memory bus enable
82 input mclk; // Main system clock
83 input [15:0] pc; // Program counter
84 input por; // Power on reset
87 //=============================================================================
88 // 1) WIRE & PARAMETER DECLARATION
89 //=============================================================================
99 parameter BRK_CTL = 0,
105 //=============================================================================
106 // 2) CONFIGURATION REGISTERS
107 //=============================================================================
110 //-----------------------------------------------------------------------------
112 // Reserved RANGE_MODE INST_EN BREAK_EN ACCESS_MODE
114 // ACCESS_MODE: - 00 : Disabled
115 // - 01 : Detect read access
116 // - 10 : Detect write access
117 // - 11 : Detect read/write access
118 // NOTE: '10' & '11' modes are not supported on the instruction flow
120 // BREAK_EN: - 0 : Watchmode enable
121 // - 1 : Break enable
123 // INST_EN: - 0 : Checks are done on the execution unit (data flow)
124 // - 1 : Checks are done on the frontend (instruction flow)
126 // RANGE_MODE: - 0 : Address match on BRK_ADDR0 or BRK_ADDR1
127 // - 1 : Address match on BRK_ADDR0->BRK_ADDR1 range
129 //-----------------------------------------------------------------------------
132 wire brk_ctl_wr = brk_reg_wr[BRK_CTL];
134 always @ (posedge mclk or posedge por)
135 if (por) brk_ctl <= 5'h00;
136 else if (brk_ctl_wr) brk_ctl <= {`HWBRK_RANGE & dbg_din[4], dbg_din[3:0]};
138 wire [7:0] brk_ctl_full = {3'b000, brk_ctl};
142 //-----------------------------------------------------------------------------
144 // Reserved RANGE_WR RANGE_RD ADDR1_WR ADDR1_RD ADDR0_WR ADDR0_RD
145 //-----------------------------------------------------------------------------
148 wire brk_stat_wr = brk_reg_wr[BRK_STAT];
149 wire [5:0] brk_stat_set = {range_wr_set & `HWBRK_RANGE,
150 range_rd_set & `HWBRK_RANGE,
151 addr1_wr_set, addr1_rd_set,
152 addr0_wr_set, addr0_rd_set};
153 wire [5:0] brk_stat_clr = ~dbg_din[5:0];
155 always @ (posedge mclk or posedge por)
156 if (por) brk_stat <= 6'h00;
157 else if (brk_stat_wr) brk_stat <= ((brk_stat & brk_stat_clr) | brk_stat_set);
158 else brk_stat <= (brk_stat | brk_stat_set);
160 wire [7:0] brk_stat_full = {2'b00, brk_stat};
161 wire brk_pnd = |brk_stat;
164 // BRK_ADDR0 Register
165 //-----------------------------------------------------------------------------
166 reg [15:0] brk_addr0;
168 wire brk_addr0_wr = brk_reg_wr[BRK_ADDR0];
170 always @ (posedge mclk or posedge por)
171 if (por) brk_addr0 <= 16'h0000;
172 else if (brk_addr0_wr) brk_addr0 <= dbg_din;
175 // BRK_ADDR1/DATA0 Register
176 //-----------------------------------------------------------------------------
177 reg [15:0] brk_addr1;
179 wire brk_addr1_wr = brk_reg_wr[BRK_ADDR1];
181 always @ (posedge mclk or posedge por)
182 if (por) brk_addr1 <= 16'h0000;
183 else if (brk_addr1_wr) brk_addr1 <= dbg_din;
186 //============================================================================
187 // 3) DATA OUTPUT GENERATION
188 //============================================================================
190 wire [15:0] brk_ctl_rd = {8'h00, brk_ctl_full} & {16{brk_reg_rd[BRK_CTL]}};
191 wire [15:0] brk_stat_rd = {8'h00, brk_stat_full} & {16{brk_reg_rd[BRK_STAT]}};
192 wire [15:0] brk_addr0_rd = brk_addr0 & {16{brk_reg_rd[BRK_ADDR0]}};
193 wire [15:0] brk_addr1_rd = brk_addr1 & {16{brk_reg_rd[BRK_ADDR1]}};
195 wire [15:0] brk_dout = brk_ctl_rd |
201 //============================================================================
202 // 4) BREAKPOINT / WATCHPOINT GENERATION
203 //============================================================================
206 //---------------------------
207 // Note: here the comparison logic is instanciated several times in order
208 // to improve the timings, at the cost of a bit more area.
210 wire equ_d_addr0 = eu_mb_en & (eu_mab==brk_addr0) & ~brk_ctl[`BRK_RANGE];
211 wire equ_d_addr1 = eu_mb_en & (eu_mab==brk_addr1) & ~brk_ctl[`BRK_RANGE];
212 wire equ_d_range = eu_mb_en & ((eu_mab>=brk_addr0) & (eu_mab<=brk_addr1)) &
213 brk_ctl[`BRK_RANGE] & `HWBRK_RANGE;
216 always @ (posedge mclk or posedge por)
217 if (por) fe_mb_en_buf <= 1'b0;
218 else fe_mb_en_buf <= fe_mb_en;
220 wire equ_i_addr0 = fe_mb_en_buf & (pc==brk_addr0) & ~brk_ctl[`BRK_RANGE];
221 wire equ_i_addr1 = fe_mb_en_buf & (pc==brk_addr1) & ~brk_ctl[`BRK_RANGE];
222 wire equ_i_range = fe_mb_en_buf & ((pc>=brk_addr0) & (pc<=brk_addr1)) &
223 brk_ctl[`BRK_RANGE] & `HWBRK_RANGE;
227 //---------------------------
229 // Detect Instruction read access
230 wire i_addr0_rd = equ_i_addr0 & brk_ctl[`BRK_I_EN];
231 wire i_addr1_rd = equ_i_addr1 & brk_ctl[`BRK_I_EN];
232 wire i_range_rd = equ_i_range & brk_ctl[`BRK_I_EN];
234 // Detect Execution-Unit write access
235 wire d_addr0_wr = equ_d_addr0 & ~brk_ctl[`BRK_I_EN] & |eu_mb_wr;
236 wire d_addr1_wr = equ_d_addr1 & ~brk_ctl[`BRK_I_EN] & |eu_mb_wr;
237 wire d_range_wr = equ_d_range & ~brk_ctl[`BRK_I_EN] & |eu_mb_wr;
239 // Detect DATA read access
240 // Whenever an "ADD r9. &0x200" instruction is executed, &0x200 will be read
241 // before being written back. In that case, the read flag should not be set.
242 // In general, We should here make sure no write access occures during the
243 // same instruction cycle before setting the read flag.
245 always @ (posedge mclk or posedge por)
246 if (por) d_rd_trig <= 3'h0;
247 else if (exec_done) d_rd_trig <= 3'h0;
248 else d_rd_trig <= {equ_d_range & ~brk_ctl[`BRK_I_EN] & ~|eu_mb_wr,
249 equ_d_addr1 & ~brk_ctl[`BRK_I_EN] & ~|eu_mb_wr,
250 equ_d_addr0 & ~brk_ctl[`BRK_I_EN] & ~|eu_mb_wr};
252 wire d_addr0_rd = d_rd_trig[0] & exec_done & ~d_addr0_wr;
253 wire d_addr1_rd = d_rd_trig[1] & exec_done & ~d_addr1_wr;
254 wire d_range_rd = d_rd_trig[2] & exec_done & ~d_range_wr;
258 assign addr0_rd_set = brk_ctl[`BRK_MODE_RD] & (d_addr0_rd | i_addr0_rd);
259 assign addr0_wr_set = brk_ctl[`BRK_MODE_WR] & d_addr0_wr;
260 assign addr1_rd_set = brk_ctl[`BRK_MODE_RD] & (d_addr1_rd | i_addr1_rd);
261 assign addr1_wr_set = brk_ctl[`BRK_MODE_WR] & d_addr1_wr;
262 assign range_rd_set = brk_ctl[`BRK_MODE_RD] & (d_range_rd | i_range_rd);
263 assign range_wr_set = brk_ctl[`BRK_MODE_WR] & d_range_wr;
267 assign brk_halt = brk_ctl[`BRK_EN] & |brk_stat_set;
270 endmodule // omsp_dbg_hwbrk
272 `include "openMSP430_undefines.v"