//---------------------------------------------------------------------------- // Copyright (C) 2009 , Olivier Girard // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions // are met: // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above copyright // notice, this list of conditions and the following disclaimer in the // documentation and/or other materials provided with the distribution. // * Neither the name of the authors nor the names of its contributors // may be used to endorse or promote products derived from this software // without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, // OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF // THE POSSIBILITY OF SUCH DAMAGE // //---------------------------------------------------------------------------- // // *File Name: omsp_register_file.v // // *Module Description: // openMSP430 Register files // // *Author(s): // - Olivier Girard, olgirard@gmail.com // //---------------------------------------------------------------------------- // $Rev: 134 $ // $LastChangedBy: olivier.girard $ // $LastChangedDate: 2012-03-22 21:31:06 +0100 (Thu, 22 Mar 2012) $ //---------------------------------------------------------------------------- `ifdef OMSP_NO_INCLUDE `else `include "openMSP430_defines.v" `endif module omsp_register_file ( // OUTPUTs cpuoff, // Turns off the CPU gie, // General interrupt enable oscoff, // Turns off LFXT1 clock input pc_sw, // Program counter software value pc_sw_wr, // Program counter software write reg_dest, // Selected register destination content reg_src, // Selected register source content scg0, // System clock generator 1. Turns off the DCO scg1, // System clock generator 1. Turns off the SMCLK status, // R2 Status {V,N,Z,C} // INPUTs alu_stat, // ALU Status {V,N,Z,C} alu_stat_wr, // ALU Status write {V,N,Z,C} inst_bw, // Decoded Inst: byte width inst_dest, // Register destination selection inst_src, // Register source selection mclk, // Main system clock pc, // Program counter puc_rst, // Main system reset reg_dest_val, // Selected register destination value reg_dest_wr, // Write selected register destination reg_pc_call, // Trigger PC update for a CALL instruction reg_sp_val, // Stack Pointer next value reg_sp_wr, // Stack Pointer write reg_sr_wr, // Status register update for RETI instruction reg_sr_clr, // Status register clear for interrupts reg_incr, // Increment source register scan_enable // Scan enable (active during scan shifting) ); // OUTPUTs //========= output cpuoff; // Turns off the CPU output gie; // General interrupt enable output oscoff; // Turns off LFXT1 clock input output [15:0] pc_sw; // Program counter software value output pc_sw_wr; // Program counter software write output [15:0] reg_dest; // Selected register destination content output [15:0] reg_src; // Selected register source content output scg0; // System clock generator 1. Turns off the DCO output scg1; // System clock generator 1. Turns off the SMCLK output [3:0] status; // R2 Status {V,N,Z,C} // INPUTs //========= input [3:0] alu_stat; // ALU Status {V,N,Z,C} input [3:0] alu_stat_wr; // ALU Status write {V,N,Z,C} input inst_bw; // Decoded Inst: byte width input [15:0] inst_dest; // Register destination selection input [15:0] inst_src; // Register source selection input mclk; // Main system clock input [15:0] pc; // Program counter input puc_rst; // Main system reset input [15:0] reg_dest_val; // Selected register destination value input reg_dest_wr; // Write selected register destination input reg_pc_call; // Trigger PC update for a CALL instruction input [15:0] reg_sp_val; // Stack Pointer next value input reg_sp_wr; // Stack Pointer write input reg_sr_wr; // Status register update for RETI instruction input reg_sr_clr; // Status register clear for interrupts input reg_incr; // Increment source register input scan_enable; // Scan enable (active during scan shifting) //============================================================================= // 1) AUTOINCREMENT UNIT //============================================================================= wire [15:0] inst_src_in; wire [15:0] incr_op = (inst_bw & ~inst_src_in[1]) ? 16'h0001 : 16'h0002; wire [15:0] reg_incr_val = reg_src+incr_op; wire [15:0] reg_dest_val_in = inst_bw ? {8'h00,reg_dest_val[7:0]} : reg_dest_val; //============================================================================= // 2) SPECIAL REGISTERS (R1/R2/R3) //============================================================================= // Source input selection mask (for interrupt support) //----------------------------------------------------- assign inst_src_in = reg_sr_clr ? 16'h0004 : inst_src; // R0: Program counter //--------------------- wire [15:0] r0 = pc; wire [15:0] pc_sw = reg_dest_val_in; wire pc_sw_wr = (inst_dest[0] & reg_dest_wr) | reg_pc_call; // R1: Stack pointer //------------------- reg [15:0] r1; wire r1_wr = inst_dest[1] & reg_dest_wr; wire r1_inc = inst_src_in[1] & reg_incr; `ifdef CLOCK_GATING wire r1_en = r1_wr | reg_sp_wr | r1_inc; wire mclk_r1; omsp_clock_gate clock_gate_r1 (.gclk(mclk_r1), .clk (mclk), .enable(r1_en), .scan_enable(scan_enable)); `else wire mclk_r1 = mclk; `endif always @(posedge mclk_r1 or posedge puc_rst) if (puc_rst) r1 <= 16'h0000; else if (r1_wr) r1 <= reg_dest_val_in & 16'hfffe; else if (reg_sp_wr) r1 <= reg_sp_val & 16'hfffe; `ifdef CLOCK_GATING else r1 <= reg_incr_val & 16'hfffe; `else else if (r1_inc) r1 <= reg_incr_val & 16'hfffe; `endif // R2: Status register //--------------------- reg [15:0] r2; wire r2_wr = (inst_dest[2] & reg_dest_wr) | reg_sr_wr; `ifdef CLOCK_GATING // -- WITH CLOCK GATING -- wire r2_c = alu_stat_wr[0] ? alu_stat[0] : reg_dest_val_in[0]; // C wire r2_z = alu_stat_wr[1] ? alu_stat[1] : reg_dest_val_in[1]; // Z wire r2_n = alu_stat_wr[2] ? alu_stat[2] : reg_dest_val_in[2]; // N wire [7:3] r2_nxt = r2_wr ? reg_dest_val_in[7:3] : r2[7:3]; wire r2_v = alu_stat_wr[3] ? alu_stat[3] : reg_dest_val_in[8]; // V wire r2_en = |alu_stat_wr | r2_wr | reg_sr_clr; wire mclk_r2; omsp_clock_gate clock_gate_r2 (.gclk(mclk_r2), .clk (mclk), .enable(r2_en), .scan_enable(scan_enable)); `else // -- WITHOUT CLOCK GATING -- wire r2_c = alu_stat_wr[0] ? alu_stat[0] : r2_wr ? reg_dest_val_in[0] : r2[0]; // C wire r2_z = alu_stat_wr[1] ? alu_stat[1] : r2_wr ? reg_dest_val_in[1] : r2[1]; // Z wire r2_n = alu_stat_wr[2] ? alu_stat[2] : r2_wr ? reg_dest_val_in[2] : r2[2]; // N wire [7:3] r2_nxt = r2_wr ? reg_dest_val_in[7:3] : r2[7:3]; wire r2_v = alu_stat_wr[3] ? alu_stat[3] : r2_wr ? reg_dest_val_in[8] : r2[8]; // V wire mclk_r2 = mclk; `endif `ifdef ASIC `ifdef CPUOFF_EN wire [15:0] cpuoff_mask = 16'h0010; `else wire [15:0] cpuoff_mask = 16'h0000; `endif `ifdef OSCOFF_EN wire [15:0] oscoff_mask = 16'h0020; `else wire [15:0] oscoff_mask = 16'h0000; `endif `ifdef SCG0_EN wire [15:0] scg0_mask = 16'h0040; `else wire [15:0] scg0_mask = 16'h0000; `endif `ifdef SCG1_EN wire [15:0] scg1_mask = 16'h0080; `else wire [15:0] scg1_mask = 16'h0000; `endif `else wire [15:0] cpuoff_mask = 16'h0010; // For the FPGA version: - the CPUOFF mode is emulated wire [15:0] oscoff_mask = 16'h0020; // - the SCG1 mode is emulated wire [15:0] scg0_mask = 16'h0000; // - the SCG0 is not supported wire [15:0] scg1_mask = 16'h0080; // - the SCG1 mode is emulated `endif wire [15:0] r2_mask = cpuoff_mask | oscoff_mask | scg0_mask | scg1_mask | 16'h010f; always @(posedge mclk_r2 or posedge puc_rst) if (puc_rst) r2 <= 16'h0000; else if (reg_sr_clr) r2 <= 16'h0000; else r2 <= {7'h00, r2_v, r2_nxt, r2_n, r2_z, r2_c} & r2_mask; assign status = {r2[8], r2[2:0]}; assign gie = r2[3]; assign cpuoff = r2[4] | (r2_nxt[4] & r2_wr & cpuoff_mask[4]); assign oscoff = r2[5]; assign scg0 = r2[6]; assign scg1 = r2[7]; // R3: Constant generator //------------------------------------------------------------- // Note: the auto-increment feature is not implemented for R3 // because the @R3+ addressing mode is used for constant // generation (#-1). reg [15:0] r3; wire r3_wr = inst_dest[3] & reg_dest_wr; `ifdef CLOCK_GATING wire r3_en = r3_wr; wire mclk_r3; omsp_clock_gate clock_gate_r3 (.gclk(mclk_r3), .clk (mclk), .enable(r3_en), .scan_enable(scan_enable)); `else wire mclk_r3 = mclk; `endif always @(posedge mclk_r3 or posedge puc_rst) if (puc_rst) r3 <= 16'h0000; `ifdef CLOCK_GATING else r3 <= reg_dest_val_in; `else else if (r3_wr) r3 <= reg_dest_val_in; `endif //============================================================================= // 4) GENERAL PURPOSE REGISTERS (R4...R15) //============================================================================= // R4 //------------ reg [15:0] r4; wire r4_wr = inst_dest[4] & reg_dest_wr; wire r4_inc = inst_src_in[4] & reg_incr; `ifdef CLOCK_GATING wire r4_en = r4_wr | r4_inc; wire mclk_r4; omsp_clock_gate clock_gate_r4 (.gclk(mclk_r4), .clk (mclk), .enable(r4_en), .scan_enable(scan_enable)); `else wire mclk_r4 = mclk; `endif always @(posedge mclk_r4 or posedge puc_rst) if (puc_rst) r4 <= 16'h0000; else if (r4_wr) r4 <= reg_dest_val_in; `ifdef CLOCK_GATING else r4 <= reg_incr_val; `else else if (r4_inc) r4 <= reg_incr_val; `endif // R5 //------------ reg [15:0] r5; wire r5_wr = inst_dest[5] & reg_dest_wr; wire r5_inc = inst_src_in[5] & reg_incr; `ifdef CLOCK_GATING wire r5_en = r5_wr | r5_inc; wire mclk_r5; omsp_clock_gate clock_gate_r5 (.gclk(mclk_r5), .clk (mclk), .enable(r5_en), .scan_enable(scan_enable)); `else wire mclk_r5 = mclk; `endif always @(posedge mclk_r5 or posedge puc_rst) if (puc_rst) r5 <= 16'h0000; else if (r5_wr) r5 <= reg_dest_val_in; `ifdef CLOCK_GATING else r5 <= reg_incr_val; `else else if (r5_inc) r5 <= reg_incr_val; `endif // R6 //------------ reg [15:0] r6; wire r6_wr = inst_dest[6] & reg_dest_wr; wire r6_inc = inst_src_in[6] & reg_incr; `ifdef CLOCK_GATING wire r6_en = r6_wr | r6_inc; wire mclk_r6; omsp_clock_gate clock_gate_r6 (.gclk(mclk_r6), .clk (mclk), .enable(r6_en), .scan_enable(scan_enable)); `else wire mclk_r6 = mclk; `endif always @(posedge mclk_r6 or posedge puc_rst) if (puc_rst) r6 <= 16'h0000; else if (r6_wr) r6 <= reg_dest_val_in; `ifdef CLOCK_GATING else r6 <= reg_incr_val; `else else if (r6_inc) r6 <= reg_incr_val; `endif // R7 //------------ reg [15:0] r7; wire r7_wr = inst_dest[7] & reg_dest_wr; wire r7_inc = inst_src_in[7] & reg_incr; `ifdef CLOCK_GATING wire r7_en = r7_wr | r7_inc; wire mclk_r7; omsp_clock_gate clock_gate_r7 (.gclk(mclk_r7), .clk (mclk), .enable(r7_en), .scan_enable(scan_enable)); `else wire mclk_r7 = mclk; `endif always @(posedge mclk_r7 or posedge puc_rst) if (puc_rst) r7 <= 16'h0000; else if (r7_wr) r7 <= reg_dest_val_in; `ifdef CLOCK_GATING else r7 <= reg_incr_val; `else else if (r7_inc) r7 <= reg_incr_val; `endif // R8 //------------ reg [15:0] r8; wire r8_wr = inst_dest[8] & reg_dest_wr; wire r8_inc = inst_src_in[8] & reg_incr; `ifdef CLOCK_GATING wire r8_en = r8_wr | r8_inc; wire mclk_r8; omsp_clock_gate clock_gate_r8 (.gclk(mclk_r8), .clk (mclk), .enable(r8_en), .scan_enable(scan_enable)); `else wire mclk_r8 = mclk; `endif always @(posedge mclk_r8 or posedge puc_rst) if (puc_rst) r8 <= 16'h0000; else if (r8_wr) r8 <= reg_dest_val_in; `ifdef CLOCK_GATING else r8 <= reg_incr_val; `else else if (r8_inc) r8 <= reg_incr_val; `endif // R9 //------------ reg [15:0] r9; wire r9_wr = inst_dest[9] & reg_dest_wr; wire r9_inc = inst_src_in[9] & reg_incr; `ifdef CLOCK_GATING wire r9_en = r9_wr | r9_inc; wire mclk_r9; omsp_clock_gate clock_gate_r9 (.gclk(mclk_r9), .clk (mclk), .enable(r9_en), .scan_enable(scan_enable)); `else wire mclk_r9 = mclk; `endif always @(posedge mclk_r9 or posedge puc_rst) if (puc_rst) r9 <= 16'h0000; else if (r9_wr) r9 <= reg_dest_val_in; `ifdef CLOCK_GATING else r9 <= reg_incr_val; `else else if (r9_inc) r9 <= reg_incr_val; `endif // R10 //------------ reg [15:0] r10; wire r10_wr = inst_dest[10] & reg_dest_wr; wire r10_inc = inst_src_in[10] & reg_incr; `ifdef CLOCK_GATING wire r10_en = r10_wr | r10_inc; wire mclk_r10; omsp_clock_gate clock_gate_r10 (.gclk(mclk_r10), .clk (mclk), .enable(r10_en), .scan_enable(scan_enable)); `else wire mclk_r10 = mclk; `endif always @(posedge mclk_r10 or posedge puc_rst) if (puc_rst) r10 <= 16'h0000; else if (r10_wr) r10 <= reg_dest_val_in; `ifdef CLOCK_GATING else r10 <= reg_incr_val; `else else if (r10_inc) r10 <= reg_incr_val; `endif // R11 //------------ reg [15:0] r11; wire r11_wr = inst_dest[11] & reg_dest_wr; wire r11_inc = inst_src_in[11] & reg_incr; `ifdef CLOCK_GATING wire r11_en = r11_wr | r11_inc; wire mclk_r11; omsp_clock_gate clock_gate_r11 (.gclk(mclk_r11), .clk (mclk), .enable(r11_en), .scan_enable(scan_enable)); `else wire mclk_r11 = mclk; `endif always @(posedge mclk_r11 or posedge puc_rst) if (puc_rst) r11 <= 16'h0000; else if (r11_wr) r11 <= reg_dest_val_in; `ifdef CLOCK_GATING else r11 <= reg_incr_val; `else else if (r11_inc) r11 <= reg_incr_val; `endif // R12 //------------ reg [15:0] r12; wire r12_wr = inst_dest[12] & reg_dest_wr; wire r12_inc = inst_src_in[12] & reg_incr; `ifdef CLOCK_GATING wire r12_en = r12_wr | r12_inc; wire mclk_r12; omsp_clock_gate clock_gate_r12 (.gclk(mclk_r12), .clk (mclk), .enable(r12_en), .scan_enable(scan_enable)); `else wire mclk_r12 = mclk; `endif always @(posedge mclk_r12 or posedge puc_rst) if (puc_rst) r12 <= 16'h0000; else if (r12_wr) r12 <= reg_dest_val_in; `ifdef CLOCK_GATING else r12 <= reg_incr_val; `else else if (r12_inc) r12 <= reg_incr_val; `endif // R13 //------------ reg [15:0] r13; wire r13_wr = inst_dest[13] & reg_dest_wr; wire r13_inc = inst_src_in[13] & reg_incr; `ifdef CLOCK_GATING wire r13_en = r13_wr | r13_inc; wire mclk_r13; omsp_clock_gate clock_gate_r13 (.gclk(mclk_r13), .clk (mclk), .enable(r13_en), .scan_enable(scan_enable)); `else wire mclk_r13 = mclk; `endif always @(posedge mclk_r13 or posedge puc_rst) if (puc_rst) r13 <= 16'h0000; else if (r13_wr) r13 <= reg_dest_val_in; `ifdef CLOCK_GATING else r13 <= reg_incr_val; `else else if (r13_inc) r13 <= reg_incr_val; `endif // R14 //------------ reg [15:0] r14; wire r14_wr = inst_dest[14] & reg_dest_wr; wire r14_inc = inst_src_in[14] & reg_incr; `ifdef CLOCK_GATING wire r14_en = r14_wr | r14_inc; wire mclk_r14; omsp_clock_gate clock_gate_r14 (.gclk(mclk_r14), .clk (mclk), .enable(r14_en), .scan_enable(scan_enable)); `else wire mclk_r14 = mclk; `endif always @(posedge mclk_r14 or posedge puc_rst) if (puc_rst) r14 <= 16'h0000; else if (r14_wr) r14 <= reg_dest_val_in; `ifdef CLOCK_GATING else r14 <= reg_incr_val; `else else if (r14_inc) r14 <= reg_incr_val; `endif // R15 //------------ reg [15:0] r15; wire r15_wr = inst_dest[15] & reg_dest_wr; wire r15_inc = inst_src_in[15] & reg_incr; `ifdef CLOCK_GATING wire r15_en = r15_wr | r15_inc; wire mclk_r15; omsp_clock_gate clock_gate_r15 (.gclk(mclk_r15), .clk (mclk), .enable(r15_en), .scan_enable(scan_enable)); `else wire mclk_r15 = mclk; `endif always @(posedge mclk_r15 or posedge puc_rst) if (puc_rst) r15 <= 16'h0000; else if (r15_wr) r15 <= reg_dest_val_in; `ifdef CLOCK_GATING else r15 <= reg_incr_val; `else else if (r15_inc) r15 <= reg_incr_val; `endif //============================================================================= // 5) READ MUX //============================================================================= assign reg_src = (r0 & {16{inst_src_in[0]}}) | (r1 & {16{inst_src_in[1]}}) | (r2 & {16{inst_src_in[2]}}) | (r3 & {16{inst_src_in[3]}}) | (r4 & {16{inst_src_in[4]}}) | (r5 & {16{inst_src_in[5]}}) | (r6 & {16{inst_src_in[6]}}) | (r7 & {16{inst_src_in[7]}}) | (r8 & {16{inst_src_in[8]}}) | (r9 & {16{inst_src_in[9]}}) | (r10 & {16{inst_src_in[10]}}) | (r11 & {16{inst_src_in[11]}}) | (r12 & {16{inst_src_in[12]}}) | (r13 & {16{inst_src_in[13]}}) | (r14 & {16{inst_src_in[14]}}) | (r15 & {16{inst_src_in[15]}}); assign reg_dest = (r0 & {16{inst_dest[0]}}) | (r1 & {16{inst_dest[1]}}) | (r2 & {16{inst_dest[2]}}) | (r3 & {16{inst_dest[3]}}) | (r4 & {16{inst_dest[4]}}) | (r5 & {16{inst_dest[5]}}) | (r6 & {16{inst_dest[6]}}) | (r7 & {16{inst_dest[7]}}) | (r8 & {16{inst_dest[8]}}) | (r9 & {16{inst_dest[9]}}) | (r10 & {16{inst_dest[10]}}) | (r11 & {16{inst_dest[11]}}) | (r12 & {16{inst_dest[12]}}) | (r13 & {16{inst_dest[13]}}) | (r14 & {16{inst_dest[14]}}) | (r15 & {16{inst_dest[15]}}); endmodule // omsp_register_file `ifdef OMSP_NO_INCLUDE `else `include "openMSP430_undefines.v" `endif