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[/] [openmsp430/] [trunk/] [fpga/] [actel_m1a3pl_dev_kit/] [rtl/] [verilog/] [openmsp430/] [omsp_clock_module.v] - Rev 190
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//---------------------------------------------------------------------------- // 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_clock_module.v // // *Module Description: // Basic clock module implementation. // // *Author(s): // - Olivier Girard, olgirard@gmail.com // //---------------------------------------------------------------------------- // $Rev: 103 $ // $LastChangedBy: olivier.girard $ // $LastChangedDate: 2011-03-05 15:44:48 +0100 (Sat, 05 Mar 2011) $ //---------------------------------------------------------------------------- `ifdef OMSP_NO_INCLUDE `else `include "openMSP430_defines.v" `endif module omsp_clock_module ( // OUTPUTs aclk, // ACLK aclk_en, // ACLK enable cpu_en_s, // Enable CPU code execution (synchronous) dbg_clk, // Debug unit clock dbg_en_s, // Debug interface enable (synchronous) dbg_rst, // Debug unit reset dco_enable, // Fast oscillator enable dco_wkup, // Fast oscillator wake-up (asynchronous) lfxt_enable, // Low frequency oscillator enable lfxt_wkup, // Low frequency oscillator wake-up (asynchronous) mclk, // Main system clock per_dout, // Peripheral data output por, // Power-on reset puc_pnd_set, // PUC pending set for the serial debug interface puc_rst, // Main system reset smclk, // SMCLK smclk_en, // SMCLK enable // INPUTs cpu_en, // Enable CPU code execution (asynchronous) cpuoff, // Turns off the CPU dbg_cpu_reset, // Reset CPU from debug interface dbg_en, // Debug interface enable (asynchronous) dco_clk, // Fast oscillator (fast clock) lfxt_clk, // Low frequency oscillator (typ 32kHz) mclk_enable, // Main System Clock enable mclk_wkup, // Main System Clock wake-up (asynchronous) oscoff, // Turns off LFXT1 clock input per_addr, // Peripheral address per_din, // Peripheral data input per_en, // Peripheral enable (high active) per_we, // Peripheral write enable (high active) reset_n, // Reset Pin (low active, asynchronous) scan_enable, // Scan enable (active during scan shifting) scan_mode, // Scan mode scg0, // System clock generator 1. Turns off the DCO scg1, // System clock generator 1. Turns off the SMCLK wdt_reset // Watchdog-timer reset ); // OUTPUTs //========= output aclk; // ACLK output aclk_en; // ACLK enable output cpu_en_s; // Enable CPU code execution (synchronous) output dbg_clk; // Debug unit clock output dbg_en_s; // Debug unit enable (synchronous) output dbg_rst; // Debug unit reset output dco_enable; // Fast oscillator enable output dco_wkup; // Fast oscillator wake-up (asynchronous) output lfxt_enable; // Low frequency oscillator enable output lfxt_wkup; // Low frequency oscillator wake-up (asynchronous) output mclk; // Main system clock output [15:0] per_dout; // Peripheral data output output por; // Power-on reset output puc_pnd_set; // PUC pending set for the serial debug interface output puc_rst; // Main system reset output smclk; // SMCLK output smclk_en; // SMCLK enable // INPUTs //========= input cpu_en; // Enable CPU code execution (asynchronous) input cpuoff; // Turns off the CPU input dbg_cpu_reset;// Reset CPU from debug interface input dbg_en; // Debug interface enable (asynchronous) input dco_clk; // Fast oscillator (fast clock) input lfxt_clk; // Low frequency oscillator (typ 32kHz) input mclk_enable; // Main System Clock enable input mclk_wkup; // Main System Clock wake-up (asynchronous) input oscoff; // Turns off LFXT1 clock input input [13:0] per_addr; // Peripheral address input [15:0] per_din; // Peripheral data input input per_en; // Peripheral enable (high active) input [1:0] per_we; // Peripheral write enable (high active) input reset_n; // Reset Pin (low active, asynchronous) input scan_enable; // Scan enable (active during scan shifting) input scan_mode; // Scan mode input scg0; // System clock generator 1. Turns off the DCO input scg1; // System clock generator 1. Turns off the SMCLK input wdt_reset; // Watchdog-timer reset //============================================================================= // 1) WIRES & PARAMETER DECLARATION //============================================================================= // Register base address (must be aligned to decoder bit width) parameter [14:0] BASE_ADDR = 15'h0050; // Decoder bit width (defines how many bits are considered for address decoding) parameter DEC_WD = 4; // Register addresses offset parameter [DEC_WD-1:0] BCSCTL1 = 'h7, BCSCTL2 = 'h8; // Register one-hot decoder utilities parameter DEC_SZ = (1 << DEC_WD); parameter [DEC_SZ-1:0] BASE_REG = {{DEC_SZ-1{1'b0}}, 1'b1}; // Register one-hot decoder parameter [DEC_SZ-1:0] BCSCTL1_D = (BASE_REG << BCSCTL1), BCSCTL2_D = (BASE_REG << BCSCTL2); // Local wire declarations wire nodiv_mclk; wire nodiv_mclk_n; wire nodiv_smclk; //============================================================================ // 2) REGISTER DECODER //============================================================================ // Local register selection wire reg_sel = per_en & (per_addr[13:DEC_WD-1]==BASE_ADDR[14:DEC_WD]); // Register local address wire [DEC_WD-1:0] reg_addr = {1'b0, per_addr[DEC_WD-2:0]}; // Register address decode wire [DEC_SZ-1:0] reg_dec = (BCSCTL1_D & {DEC_SZ{(reg_addr==(BCSCTL1 >>1))}}) | (BCSCTL2_D & {DEC_SZ{(reg_addr==(BCSCTL2 >>1))}}); // Read/Write probes wire reg_lo_write = per_we[0] & reg_sel; wire reg_hi_write = per_we[1] & reg_sel; wire reg_read = ~|per_we & reg_sel; // Read/Write vectors wire [DEC_SZ-1:0] reg_hi_wr = reg_dec & {DEC_SZ{reg_hi_write}}; wire [DEC_SZ-1:0] reg_lo_wr = reg_dec & {DEC_SZ{reg_lo_write}}; wire [DEC_SZ-1:0] reg_rd = reg_dec & {DEC_SZ{reg_read}}; //============================================================================ // 3) REGISTERS //============================================================================ // BCSCTL1 Register //-------------- reg [7:0] bcsctl1; wire bcsctl1_wr = BCSCTL1[0] ? reg_hi_wr[BCSCTL1] : reg_lo_wr[BCSCTL1]; wire [7:0] bcsctl1_nxt = BCSCTL1[0] ? per_din[15:8] : per_din[7:0]; `ifdef ASIC_CLOCKING `ifdef ACLK_DIVIDER wire [7:0] divax_mask = 8'h30; `else wire [7:0] divax_mask = 8'h00; `endif `else wire [7:0] divax_mask = 8'h30; `endif always @ (posedge mclk or posedge puc_rst) if (puc_rst) bcsctl1 <= 8'h00; else if (bcsctl1_wr) bcsctl1 <= bcsctl1_nxt & divax_mask; // Mask unused bits // BCSCTL2 Register //-------------- reg [7:0] bcsctl2; wire bcsctl2_wr = BCSCTL2[0] ? reg_hi_wr[BCSCTL2] : reg_lo_wr[BCSCTL2]; wire [7:0] bcsctl2_nxt = BCSCTL2[0] ? per_din[15:8] : per_din[7:0]; `ifdef MCLK_MUX wire [7:0] selmx_mask = 8'h80; `else wire [7:0] selmx_mask = 8'h00; `endif `ifdef MCLK_DIVIDER wire [7:0] divmx_mask = 8'h30; `else wire [7:0] divmx_mask = 8'h00; `endif `ifdef ASIC_CLOCKING `ifdef SMCLK_MUX wire [7:0] sels_mask = 8'h08; `else wire [7:0] sels_mask = 8'h00; `endif `ifdef SMCLK_DIVIDER wire [7:0] divsx_mask = 8'h06; `else wire [7:0] divsx_mask = 8'h00; `endif `else wire [7:0] sels_mask = 8'h08; wire [7:0] divsx_mask = 8'h06; `endif always @ (posedge mclk or posedge puc_rst) if (puc_rst) bcsctl2 <= 8'h00; else if (bcsctl2_wr) bcsctl2 <= bcsctl2_nxt & ( sels_mask | divsx_mask | selmx_mask | divmx_mask); // Mask unused bits //============================================================================ // 4) DATA OUTPUT GENERATION //============================================================================ // Data output mux wire [15:0] bcsctl1_rd = {8'h00, (bcsctl1 & {8{reg_rd[BCSCTL1]}})} << (8 & {4{BCSCTL1[0]}}); wire [15:0] bcsctl2_rd = {8'h00, (bcsctl2 & {8{reg_rd[BCSCTL2]}})} << (8 & {4{BCSCTL2[0]}}); wire [15:0] per_dout = bcsctl1_rd | bcsctl2_rd; //============================================================================= // 5) DCO_CLK / LFXT_CLK INTERFACES (WAKEUP, ENABLE, ...) //============================================================================= `ifdef ASIC_CLOCKING wire cpuoff_and_mclk_enable; omsp_and_gate and_cpuoff_mclk_en (.y(cpuoff_and_mclk_enable), .a(cpuoff), .b(mclk_enable)); `endif //----------------------------------------------------------- // 5.1) HIGH SPEED SYSTEM CLOCK GENERATOR (DCO_CLK) //----------------------------------------------------------- // Note1: switching off the DCO osillator is only // supported in ASIC mode with SCG0 low power mode // // Note2: unlike the original MSP430 specification, // we allow to switch off the DCO even // if it is selected by MCLK or SMCLK. wire por_a; wire dco_wkup; wire cpu_en_wkup; `ifdef SCG0_EN // The DCO oscillator is synchronously disabled if: // - the cpu pin is disabled (in that case, wait for mclk_enable==0) // - the debug interface is disabled // - SCG0 is set (in that case, wait for the mclk_enable==0 if selected by SELMx) // // Note that we make extensive use of the AND gate module in order // to prevent glitch propagation on the wakeup logic cone. wire cpu_enabled_with_dco; wire dco_not_enabled_by_dbg; wire dco_disable_by_scg0; wire dco_disable_by_cpu_en; wire dco_enable_nxt; omsp_and_gate and_dco_dis1 (.y(cpu_enabled_with_dco), .a(~bcsctl2[`SELMx]), .b(cpuoff_and_mclk_enable)); omsp_and_gate and_dco_dis2 (.y(dco_not_enabled_by_dbg), .a(~dbg_en_s), .b(~cpu_enabled_with_dco)); omsp_and_gate and_dco_dis3 (.y(dco_disable_by_scg0), .a(scg0), .b(dco_not_enabled_by_dbg)); omsp_and_gate and_dco_dis4 (.y(dco_disable_by_cpu_en), .a(~cpu_en_s), .b(~mclk_enable)); omsp_and_gate and_dco_dis5 (.y(dco_enable_nxt), .a(~dco_disable_by_scg0), .b(~dco_disable_by_cpu_en)); // Register to prevent glitch propagation reg dco_disable; always @(posedge nodiv_mclk_n or posedge por) if (por) dco_disable <= 1'b1; else dco_disable <= ~dco_enable_nxt; // Note that a synchronizer is required if the MCLK mux is included wire dco_clk_n = ~dco_clk; `ifdef MCLK_MUX omsp_sync_cell sync_cell_dco_disable ( .data_out (dco_enable), .data_in (~dco_disable), .clk (dco_clk_n), .rst (por) ); `else assign dco_enable = ~dco_disable; `endif // The DCO oscillator will get an asynchronous wakeup if: // - the MCLK generates a wakeup (only if the MCLK mux selects dco_clk) // - if the DCO wants to be synchronously enabled (i.e dco_enable_nxt=1) wire dco_mclk_wkup; wire dco_en_wkup; omsp_and_gate and_dco_mclk_wkup (.y(dco_mclk_wkup), .a(mclk_wkup), .b(~bcsctl2[`SELMx])); omsp_and_gate and_dco_en_wkup (.y(dco_en_wkup), .a(~dco_enable), .b(dco_enable_nxt)); wire dco_wkup_set = dco_mclk_wkup | dco_en_wkup | cpu_en_wkup; // Scan MUX for the asynchronous SET wire dco_wkup_set_scan; omsp_scan_mux scan_mux_dco_wkup ( .scan_mode (scan_mode), .data_in_scan (por_a), .data_in_func (dco_wkup_set | por), .data_out (dco_wkup_set_scan) ); // Scan MUX to increase coverage wire dco_wkup_clear; omsp_scan_mux scan_mux_dco_wkup_clear ( .scan_mode (scan_mode), .data_in_scan (dco_wkup_set), .data_in_func (1'b1), .data_out (dco_wkup_clear) ); // The wakeup is asynchronously set, synchronously released wire dco_wkup_n; omsp_sync_cell sync_cell_dco_wkup ( .data_out (dco_wkup_n), .data_in (dco_wkup_clear), .clk (dco_clk_n), .rst (dco_wkup_set_scan) ); omsp_and_gate and_dco_wkup (.y(dco_wkup), .a(~dco_wkup_n), .b(cpu_en)); `else assign dco_enable = 1'b1; assign dco_wkup = 1'b1; `endif //----------------------------------------------------------- // 5.2) LOW FREQUENCY CRYSTAL CLOCK GENERATOR (LFXT_CLK) //----------------------------------------------------------- // ASIC MODE //------------------------------------------------ // Note: unlike the original MSP430 specification, // we allow to switch off the LFXT even // if it is selected by MCLK or SMCLK. `ifdef ASIC_CLOCKING `ifdef OSCOFF_EN // The LFXT is synchronously disabled if: // - the cpu pin is disabled (in that case, wait for mclk_enable==0) // - the debug interface is disabled // - OSCOFF is set (in that case, wait for the mclk_enable==0 if selected by SELMx) wire cpu_enabled_with_lfxt; wire lfxt_not_enabled_by_dbg; wire lfxt_disable_by_oscoff; wire lfxt_disable_by_cpu_en; wire lfxt_enable_nxt; omsp_and_gate and_lfxt_dis1 (.y(cpu_enabled_with_lfxt), .a(bcsctl2[`SELMx]), .b(cpuoff_and_mclk_enable)); omsp_and_gate and_lfxt_dis2 (.y(lfxt_not_enabled_by_dbg), .a(~dbg_en_s), .b(~cpu_enabled_with_lfxt)); omsp_and_gate and_lfxt_dis3 (.y(lfxt_disable_by_oscoff), .a(oscoff), .b(lfxt_not_enabled_by_dbg)); omsp_and_gate and_lfxt_dis4 (.y(lfxt_disable_by_cpu_en), .a(~cpu_en_s), .b(~mclk_enable)); omsp_and_gate and_lfxt_dis5 (.y(lfxt_enable_nxt), .a(~lfxt_disable_by_oscoff), .b(~lfxt_disable_by_cpu_en)); // Register to prevent glitch propagation reg lfxt_disable; always @(posedge nodiv_mclk_n or posedge por) if (por) lfxt_disable <= 1'b1; else lfxt_disable <= ~lfxt_enable_nxt; // Synchronize the OSCOFF control signal to the LFXT clock domain wire lfxt_clk_n = ~lfxt_clk; omsp_sync_cell sync_cell_lfxt_disable ( .data_out (lfxt_enable), .data_in (~lfxt_disable), .clk (lfxt_clk_n), .rst (por) ); // The LFXT will get an asynchronous wakeup if: // - the MCLK generates a wakeup (only if the MCLK mux selects lfxt_clk) // - if the LFXT wants to be synchronously enabled (i.e lfxt_enable_nxt=1) wire lfxt_mclk_wkup; wire lfxt_en_wkup; omsp_and_gate and_lfxt_mclk_wkup (.y(lfxt_mclk_wkup), .a(mclk_wkup), .b(bcsctl2[`SELMx])); omsp_and_gate and_lfxt_en_wkup (.y(lfxt_en_wkup), .a(~lfxt_enable), .b(lfxt_enable_nxt)); wire lfxt_wkup_set = lfxt_mclk_wkup | lfxt_en_wkup | cpu_en_wkup; // Scan MUX for the asynchronous SET wire lfxt_wkup_set_scan; omsp_scan_mux scan_mux_lfxt_wkup ( .scan_mode (scan_mode), .data_in_scan (por_a), .data_in_func (lfxt_wkup_set | por), .data_out (lfxt_wkup_set_scan) ); // Scan MUX to increase coverage wire lfxt_wkup_clear; omsp_scan_mux scan_mux_lfxt_wkup_clear ( .scan_mode (scan_mode), .data_in_scan (lfxt_wkup_set), .data_in_func (1'b1), .data_out (lfxt_wkup_clear) ); // The wakeup is asynchronously set, synchronously released wire lfxt_wkup_n; omsp_sync_cell sync_cell_lfxt_wkup ( .data_out (lfxt_wkup_n), .data_in (lfxt_wkup_clear), .clk (lfxt_clk_n), .rst (lfxt_wkup_set_scan) ); omsp_and_gate and_lfxt_wkup (.y(lfxt_wkup), .a(~lfxt_wkup_n), .b(cpu_en)); `else assign lfxt_enable = 1'b1; assign lfxt_wkup = 1'b0; `endif // FPGA MODE //--------------------------------------- // Synchronize LFXT_CLK & edge detection `else wire lfxt_clk_s; omsp_sync_cell sync_cell_lfxt_clk ( .data_out (lfxt_clk_s), .data_in (lfxt_clk), .clk (mclk), .rst (por) ); reg lfxt_clk_dly; always @ (posedge mclk or posedge por) if (por) lfxt_clk_dly <= 1'b0; else lfxt_clk_dly <= lfxt_clk_s; wire lfxt_clk_en = (lfxt_clk_s & ~lfxt_clk_dly) & ~(oscoff & ~bcsctl2[`SELS]); assign lfxt_enable = 1'b1; assign lfxt_wkup = 1'b0; `endif //============================================================================= // 6) CLOCK GENERATION //============================================================================= //----------------------------------------------------------- // 6.1) GLOBAL CPU ENABLE //----------------------------------------------------------- // ACLK and SMCLK are directly switched-off // with the cpu_en pin (after synchronization). // MCLK will be switched off once the CPU reaches // its IDLE state (through the mclk_enable signal) // Synchronize CPU_EN signal to the MCLK domain //---------------------------------------------- `ifdef SYNC_CPU_EN omsp_sync_cell sync_cell_cpu_en ( .data_out (cpu_en_s), .data_in (cpu_en), .clk (nodiv_mclk), .rst (por) ); omsp_and_gate and_cpu_en_wkup (.y(cpu_en_wkup), .a(cpu_en), .b(~cpu_en_s)); `else assign cpu_en_s = cpu_en; assign cpu_en_wkup = 1'b0; `endif // Synchronize CPU_EN signal to the ACLK domain //---------------------------------------------- `ifdef LFXT_DOMAIN wire cpu_en_aux_s; omsp_sync_cell sync_cell_cpu_aux_en ( .data_out (cpu_en_aux_s), .data_in (cpu_en), .clk (lfxt_clk), .rst (por) ); `else wire cpu_en_aux_s = cpu_en_s; `endif // Synchronize CPU_EN signal to the SMCLK domain //---------------------------------------------- // Note: the synchronizer is only required if there is a SMCLK_MUX `ifdef ASIC_CLOCKING `ifdef SMCLK_MUX wire cpu_en_sm_s; omsp_sync_cell sync_cell_cpu_sm_en ( .data_out (cpu_en_sm_s), .data_in (cpu_en), .clk (nodiv_smclk), .rst (por) ); `else wire cpu_en_sm_s = cpu_en_s; `endif `endif //----------------------------------------------------------- // 6.2) MCLK GENERATION //----------------------------------------------------------- // Clock MUX //---------------------------- `ifdef MCLK_MUX omsp_clock_mux clock_mux_mclk ( .clk_out (nodiv_mclk), .clk_in0 (dco_clk), .clk_in1 (lfxt_clk), .reset (por), .scan_mode (scan_mode), .select (bcsctl2[`SELMx]) ); `else assign nodiv_mclk = dco_clk; `endif assign nodiv_mclk_n = ~nodiv_mclk; // Wakeup synchronizer //---------------------------- wire mclk_wkup_s; `ifdef CPUOFF_EN omsp_sync_cell sync_cell_mclk_wkup ( .data_out (mclk_wkup_s), .data_in (mclk_wkup), .clk (nodiv_mclk), .rst (puc_rst) ); `else assign mclk_wkup_s = 1'b0; `endif // Clock Divider //---------------------------- // No need for extra synchronizer as bcsctl2 // comes from the same clock domain. `ifdef CPUOFF_EN wire mclk_active = mclk_enable | mclk_wkup_s | (dbg_en_s & cpu_en_s); `else wire mclk_active = 1'b1; `endif `ifdef MCLK_DIVIDER reg [2:0] mclk_div; always @ (posedge nodiv_mclk or posedge puc_rst) if (puc_rst) mclk_div <= 3'h0; else if ((bcsctl2[`DIVMx]!=2'b00)) mclk_div <= mclk_div+3'h1; wire mclk_div_en = mclk_active & ((bcsctl2[`DIVMx]==2'b00) ? 1'b1 : (bcsctl2[`DIVMx]==2'b01) ? mclk_div[0] : (bcsctl2[`DIVMx]==2'b10) ? &mclk_div[1:0] : &mclk_div[2:0]); `else wire mclk_div_en = mclk_active; `endif // Generate main system clock //---------------------------- `ifdef MCLK_CGATE omsp_clock_gate clock_gate_mclk ( .gclk (mclk), .clk (nodiv_mclk), .enable (mclk_div_en), .scan_enable (scan_enable) ); `else assign mclk = nodiv_mclk; `endif //----------------------------------------------------------- // 6.3) ACLK GENERATION //----------------------------------------------------------- // ASIC MODE //---------------------------- `ifdef ASIC_CLOCKING `ifdef ACLK_DIVIDER `ifdef LFXT_DOMAIN wire nodiv_aclk = lfxt_clk; // Local Reset synchronizer wire puc_lfxt_rst; wire puc_lfxt_noscan_n; omsp_sync_cell sync_cell_puc_lfxt ( .data_out (puc_lfxt_noscan_n), .data_in (1'b1), .clk (nodiv_aclk), .rst (puc_rst) ); omsp_scan_mux scan_mux_puc_lfxt ( .scan_mode (scan_mode), .data_in_scan (por_a), .data_in_func (~puc_lfxt_noscan_n), .data_out (puc_lfxt_rst) ); // Local synchronizer for the bcsctl1.DIVAx configuration // (note that we can live with a full bus synchronizer as // it won't hurt if we get a wrong DIVAx value for a single clock cycle) reg [1:0] divax_s; reg [1:0] divax_ss; always @ (posedge nodiv_aclk or posedge puc_lfxt_rst) if (puc_lfxt_rst) begin divax_s <= 2'h0; divax_ss <= 2'h0; end else begin divax_s <= bcsctl1[`DIVAx]; divax_ss <= divax_s; end // If the OSCOFF mode is enabled synchronize OSCOFF signal wire oscoff_s; `ifdef OSCOFF_EN omsp_sync_cell sync_cell_oscoff ( .data_out (oscoff_s), .data_in (oscoff), .clk (nodiv_aclk), .rst (puc_lfxt_rst) ); `else assign oscoff_s = 1'b0; `endif `else wire puc_lfxt_rst = puc_rst; wire nodiv_aclk = dco_clk; wire [1:0] divax_ss = bcsctl1[`DIVAx]; wire oscoff_s = oscoff; `endif // Divider reg [2:0] aclk_div; always @ (posedge nodiv_aclk or posedge puc_lfxt_rst) if (puc_lfxt_rst) aclk_div <= 3'h0; else if ((divax_ss!=2'b00)) aclk_div <= aclk_div+3'h1; wire aclk_div_en = cpu_en_aux_s & ~oscoff_s & ((divax_ss==2'b00) ? 1'b1 : (divax_ss==2'b01) ? aclk_div[0] : (divax_ss==2'b10) ? &aclk_div[1:0] : &aclk_div[2:0]); // Clock gate omsp_clock_gate clock_gate_aclk ( .gclk (aclk), .clk (nodiv_aclk), .enable (aclk_div_en), .scan_enable (scan_enable) ); `else `ifdef LFXT_DOMAIN assign aclk = lfxt_clk; `else assign aclk = dco_clk; `endif `endif assign aclk_en = 1'b1; // FPGA MODE //---------------------------- `else reg aclk_en; reg [2:0] aclk_div; wire aclk_en_nxt = lfxt_clk_en & ((bcsctl1[`DIVAx]==2'b00) ? 1'b1 : (bcsctl1[`DIVAx]==2'b01) ? aclk_div[0] : (bcsctl1[`DIVAx]==2'b10) ? &aclk_div[1:0] : &aclk_div[2:0]); always @ (posedge mclk or posedge puc_rst) if (puc_rst) aclk_div <= 3'h0; else if ((bcsctl1[`DIVAx]!=2'b00) & lfxt_clk_en) aclk_div <= aclk_div+3'h1; always @ (posedge mclk or posedge puc_rst) if (puc_rst) aclk_en <= 1'b0; else aclk_en <= aclk_en_nxt & cpu_en_s; assign aclk = mclk; `endif //----------------------------------------------------------- // 6.4) SMCLK GENERATION //----------------------------------------------------------- // Clock MUX //---------------------------- `ifdef SMCLK_MUX omsp_clock_mux clock_mux_smclk ( .clk_out (nodiv_smclk), .clk_in0 (dco_clk), .clk_in1 (lfxt_clk), .reset (por), .scan_mode (scan_mode), .select (bcsctl2[`SELS]) ); `else assign nodiv_smclk = dco_clk; `endif // ASIC MODE //---------------------------- `ifdef ASIC_CLOCKING `ifdef SMCLK_MUX // Synchronizers //------------------------------------------------------ // When the SMCLK MUX is enabled, the reset and DIVSx // and SCG1 signals must be synchronized, otherwise not. // Local Reset synchronizer wire puc_sm_noscan_n; wire puc_sm_rst; omsp_sync_cell sync_cell_puc_sm ( .data_out (puc_sm_noscan_n), .data_in (1'b1), .clk (nodiv_smclk), .rst (puc_rst) ); omsp_scan_mux scan_mux_puc_sm ( .scan_mode (scan_mode), .data_in_scan (por_a), .data_in_func (~puc_sm_noscan_n), .data_out (puc_sm_rst) ); // SCG1 synchronizer `ifdef SCG1_EN wire scg1_s; omsp_sync_cell sync_cell_scg1 ( .data_out (scg1_s), .data_in (scg1), .clk (nodiv_smclk), .rst (puc_sm_rst) ); `else wire scg1_s = 1'b0; `endif `ifdef SMCLK_DIVIDER // Local synchronizer for the bcsctl2.DIVSx configuration // (note that we can live with a full bus synchronizer as // it won't hurt if we get a wrong DIVSx value for a single clock cycle) reg [1:0] divsx_s; reg [1:0] divsx_ss; always @ (posedge nodiv_smclk or posedge puc_sm_rst) if (puc_sm_rst) begin divsx_s <= 2'h0; divsx_ss <= 2'h0; end else begin divsx_s <= bcsctl2[`DIVSx]; divsx_ss <= divsx_s; end `endif `else wire puc_sm_rst = puc_rst; wire [1:0] divsx_ss = bcsctl2[`DIVSx]; wire scg1_s = scg1; `endif // Clock Divider //---------------------------- `ifdef SMCLK_DIVIDER reg [2:0] smclk_div; always @ (posedge nodiv_smclk or posedge puc_sm_rst) if (puc_sm_rst) smclk_div <= 3'h0; else if ((divsx_ss!=2'b00)) smclk_div <= smclk_div+3'h1; wire smclk_div_en = cpu_en_sm_s & ~scg1_s & ((divsx_ss==2'b00) ? 1'b1 : (divsx_ss==2'b01) ? smclk_div[0] : (divsx_ss==2'b10) ? &smclk_div[1:0] : &smclk_div[2:0]); `else `ifdef SCG1_EN wire smclk_div_en = cpu_en_sm_s & ~scg1_s; `else wire smclk_div_en = cpu_en_sm_s; `endif `endif // Generate sub-system clock //---------------------------- `ifdef SMCLK_CGATE omsp_clock_gate clock_gate_smclk ( .gclk (smclk), .clk (nodiv_smclk), .enable (smclk_div_en), .scan_enable (scan_enable) ); `else assign smclk = nodiv_smclk; `endif assign smclk_en = 1'b1; // FPGA MODE //---------------------------- `else reg smclk_en; reg [2:0] smclk_div; wire smclk_in = ~scg1 & (bcsctl2[`SELS] ? lfxt_clk_en : 1'b1); wire smclk_en_nxt = smclk_in & ((bcsctl2[`DIVSx]==2'b00) ? 1'b1 : (bcsctl2[`DIVSx]==2'b01) ? smclk_div[0] : (bcsctl2[`DIVSx]==2'b10) ? &smclk_div[1:0] : &smclk_div[2:0]); always @ (posedge mclk or posedge puc_rst) if (puc_rst) smclk_en <= 1'b0; else smclk_en <= smclk_en_nxt & cpu_en_s; always @ (posedge mclk or posedge puc_rst) if (puc_rst) smclk_div <= 3'h0; else if ((bcsctl2[`DIVSx]!=2'b00) & smclk_in) smclk_div <= smclk_div+3'h1; wire smclk = mclk; `endif //----------------------------------------------------------- // 6.5) DEBUG INTERFACE CLOCK GENERATION (DBG_CLK) //----------------------------------------------------------- // Synchronize DBG_EN signal to MCLK domain //------------------------------------------ `ifdef DBG_EN `ifdef SYNC_DBG_EN wire dbg_en_n_s; omsp_sync_cell sync_cell_dbg_en ( .data_out (dbg_en_n_s), .data_in (~dbg_en), .clk (mclk), .rst (por) ); assign dbg_en_s = ~dbg_en_n_s; wire dbg_rst_nxt = dbg_en_n_s; `else assign dbg_en_s = dbg_en; wire dbg_rst_nxt = ~dbg_en; `endif `else assign dbg_en_s = 1'b0; wire dbg_rst_nxt = 1'b0; `endif // Serial Debug Interface Clock gate //------------------------------------------------ `ifdef DBG_EN `ifdef ASIC_CLOCKING omsp_clock_gate clock_gate_dbg_clk ( .gclk (dbg_clk), .clk (mclk), .enable (dbg_en_s), .scan_enable (scan_enable) ); `else assign dbg_clk = dco_clk; `endif `else assign dbg_clk = 1'b0; `endif //============================================================================= // 7) RESET GENERATION //============================================================================= // // Whenever the reset pin (reset_n) is deasserted, the internal resets of the // openMSP430 will be released in the following order: // 1- POR // 2- DBG_RST (if the sdi interface is enabled, i.e. dbg_en=1) // 3- PUC // // Note: releasing the DBG_RST before PUC is particularly important in order // to allow the sdi interface to halt the cpu immediately after a PUC. // // Generate synchronized POR to MCLK domain //------------------------------------------ // Asynchronous reset source assign por_a = !reset_n; wire por_noscan; // Reset Synchronizer omsp_sync_reset sync_reset_por ( .rst_s (por_noscan), .clk (nodiv_mclk), .rst_a (por_a) ); // Scan Reset Mux `ifdef ASIC omsp_scan_mux scan_mux_por ( .scan_mode (scan_mode), .data_in_scan (por_a), .data_in_func (por_noscan), .data_out (por) ); `else assign por = por_noscan; `endif // Generate synchronized reset for the SDI //------------------------------------------ `ifdef DBG_EN // Reset Generation reg dbg_rst_noscan; always @ (posedge mclk or posedge por) if (por) dbg_rst_noscan <= 1'b1; else dbg_rst_noscan <= dbg_rst_nxt; // Scan Reset Mux `ifdef ASIC omsp_scan_mux scan_mux_dbg_rst ( .scan_mode (scan_mode), .data_in_scan (por_a), .data_in_func (dbg_rst_noscan), .data_out (dbg_rst) ); `else assign dbg_rst = dbg_rst_noscan; `endif `else wire dbg_rst_noscan = 1'b1; assign dbg_rst = 1'b1; `endif // Generate main system reset (PUC_RST) //-------------------------------------- wire puc_noscan_n; wire puc_a_scan; // Asynchronous PUC reset wire puc_a = por | wdt_reset; // Synchronous PUC reset wire puc_s = dbg_cpu_reset | // With the debug interface command (dbg_en_s & dbg_rst_noscan & ~puc_noscan_n); // Sequencing making sure PUC is released // after DBG_RST if the debug interface is // enabled at power-on-reset time // Scan Reset Mux `ifdef ASIC omsp_scan_mux scan_mux_puc_rst_a ( .scan_mode (scan_mode), .data_in_scan (por_a), .data_in_func (puc_a), .data_out (puc_a_scan) ); `else assign puc_a_scan = puc_a; `endif // Reset Synchronizer // (required because of the asynchronous watchdog reset) omsp_sync_cell sync_cell_puc ( .data_out (puc_noscan_n), .data_in (~puc_s), .clk (mclk), .rst (puc_a_scan) ); // Scan Reset Mux `ifdef ASIC omsp_scan_mux scan_mux_puc_rst ( .scan_mode (scan_mode), .data_in_scan (por_a), .data_in_func (~puc_noscan_n), .data_out (puc_rst) ); `else assign puc_rst = ~puc_noscan_n; `endif // PUC pending set the serial debug interface assign puc_pnd_set = ~puc_noscan_n; endmodule // omsp_clock_module `ifdef OMSP_NO_INCLUDE `else `include "openMSP430_undefines.v" `endif
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