//---------------------------------------------------------------------------- // 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_watchdog.v // // *Module Description: // Watchdog Timer // // *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_watchdog ( // OUTPUTs per_dout, // Peripheral data output wdt_irq, // Watchdog-timer interrupt wdt_reset, // Watchdog-timer reset wdt_wkup, // Watchdog Wakeup wdtifg, // Watchdog-timer interrupt flag wdtnmies, // Watchdog-timer NMI edge selection // INPUTs aclk, // ACLK aclk_en, // ACLK enable dbg_freeze, // Freeze Watchdog counter mclk, // Main system clock per_addr, // Peripheral address per_din, // Peripheral data input per_en, // Peripheral enable (high active) per_we, // Peripheral write enable (high active) por, // Power-on reset puc_rst, // Main system reset scan_enable, // Scan enable (active during scan shifting) scan_mode, // Scan mode smclk, // SMCLK smclk_en, // SMCLK enable wdtie, // Watchdog timer interrupt enable wdtifg_irq_clr, // Watchdog-timer interrupt flag irq accepted clear wdtifg_sw_clr, // Watchdog-timer interrupt flag software clear wdtifg_sw_set // Watchdog-timer interrupt flag software set ); // OUTPUTs //========= output [15:0] per_dout; // Peripheral data output output wdt_irq; // Watchdog-timer interrupt output wdt_reset; // Watchdog-timer reset output wdt_wkup; // Watchdog Wakeup output wdtifg; // Watchdog-timer interrupt flag output wdtnmies; // Watchdog-timer NMI edge selection // INPUTs //========= input aclk; // ACLK input aclk_en; // ACLK enable input dbg_freeze; // Freeze Watchdog counter input mclk; // Main system clock 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 por; // Power-on reset input puc_rst; // Main system reset input scan_enable; // Scan enable (active during scan shifting) input scan_mode; // Scan mode input smclk; // SMCLK input smclk_en; // SMCLK enable input wdtie; // Watchdog timer interrupt enable input wdtifg_irq_clr; // Clear Watchdog-timer interrupt flag input wdtifg_sw_clr; // Watchdog-timer interrupt flag software clear input wdtifg_sw_set; // Watchdog-timer interrupt flag software set //============================================================================= // 1) PARAMETER DECLARATION //============================================================================= // Register base address (must be aligned to decoder bit width) parameter [14:0] BASE_ADDR = 15'h0120; // Decoder bit width (defines how many bits are considered for address decoding) parameter DEC_WD = 2; // Register addresses offset parameter [DEC_WD-1:0] WDTCTL = 'h0; // 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] WDTCTL_D = (BASE_REG << WDTCTL); //============================================================================ // 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 = {per_addr[DEC_WD-2:0], 1'b0}; // Register address decode wire [DEC_SZ-1:0] reg_dec = (WDTCTL_D & {DEC_SZ{(reg_addr==WDTCTL)}}); // Read/Write probes wire reg_write = |per_we & reg_sel; wire reg_read = ~|per_we & reg_sel; // Read/Write vectors wire [DEC_SZ-1:0] reg_wr = reg_dec & {DEC_SZ{reg_write}}; wire [DEC_SZ-1:0] reg_rd = reg_dec & {DEC_SZ{reg_read}}; //============================================================================ // 3) REGISTERS //============================================================================ // WDTCTL Register //----------------- // WDTNMI is not implemented and therefore masked reg [7:0] wdtctl; wire wdtctl_wr = reg_wr[WDTCTL]; `ifdef CLOCK_GATING wire mclk_wdtctl; omsp_clock_gate clock_gate_wdtctl (.gclk(mclk_wdtctl), .clk (mclk), .enable(wdtctl_wr), .scan_enable(scan_enable)); `else wire mclk_wdtctl = mclk; `endif `ifdef NMI parameter [7:0] WDTNMIES_MASK = 8'h40; `else parameter [7:0] WDTNMIES_MASK = 8'h00; `endif `ifdef ASIC `ifdef WATCHDOG_MUX parameter [7:0] WDTSSEL_MASK = 8'h04; `else parameter [7:0] WDTSSEL_MASK = 8'h00; `endif `else parameter [7:0] WDTSSEL_MASK = 8'h04; `endif parameter [7:0] WDTCTL_MASK = (8'b1001_0011 | WDTSSEL_MASK | WDTNMIES_MASK); always @ (posedge mclk_wdtctl or posedge puc_rst) if (puc_rst) wdtctl <= 8'h00; `ifdef CLOCK_GATING else wdtctl <= per_din[7:0] & WDTCTL_MASK; `else else if (wdtctl_wr) wdtctl <= per_din[7:0] & WDTCTL_MASK; `endif wire wdtpw_error = wdtctl_wr & (per_din[15:8]!=8'h5a); wire wdttmsel = wdtctl[4]; wire wdtnmies = wdtctl[6]; //============================================================================ // 4) DATA OUTPUT GENERATION //============================================================================ `ifdef NMI parameter [7:0] WDTNMI_RD_MASK = 8'h20; `else parameter [7:0] WDTNMI_RD_MASK = 8'h00; `endif `ifdef WATCHDOG_MUX parameter [7:0] WDTSSEL_RD_MASK = 8'h00; `else `ifdef WATCHDOG_NOMUX_ACLK parameter [7:0] WDTSSEL_RD_MASK = 8'h04; `else parameter [7:0] WDTSSEL_RD_MASK = 8'h00; `endif `endif parameter [7:0] WDTCTL_RD_MASK = WDTNMI_RD_MASK | WDTSSEL_RD_MASK; // Data output mux wire [15:0] wdtctl_rd = {8'h69, wdtctl | WDTCTL_RD_MASK} & {16{reg_rd[WDTCTL]}}; wire [15:0] per_dout = wdtctl_rd; //============================================================================= // 5) WATCHDOG TIMER (ASIC IMPLEMENTATION) //============================================================================= `ifdef ASIC // Watchdog clock source selection //--------------------------------- wire wdt_clk; `ifdef WATCHDOG_MUX omsp_clock_mux clock_mux_watchdog ( .clk_out (wdt_clk), .clk_in0 (smclk), .clk_in1 (aclk), .reset (puc_rst), .scan_mode (scan_mode), .select (wdtctl[2]) ); `else `ifdef WATCHDOG_NOMUX_ACLK assign wdt_clk = aclk; `else assign wdt_clk = smclk; `endif `endif // Reset synchronizer for the watchdog local clock domain //-------------------------------------------------------- wire wdt_rst_noscan; wire wdt_rst; // Reset Synchronizer omsp_sync_reset sync_reset_por ( .rst_s (wdt_rst_noscan), .clk (wdt_clk), .rst_a (puc_rst) ); // Scan Reset Mux omsp_scan_mux scan_mux_wdt_rst ( .scan_mode (scan_mode), .data_in_scan (puc_rst), .data_in_func (wdt_rst_noscan), .data_out (wdt_rst) ); // Watchog counter clear (synchronization) //----------------------------------------- // Toggle bit whenever the watchog needs to be cleared reg wdtcnt_clr_toggle; wire wdtcnt_clr_detect = (wdtctl_wr & per_din[3]); always @ (posedge mclk or posedge puc_rst) if (puc_rst) wdtcnt_clr_toggle <= 1'b0; else if (wdtcnt_clr_detect) wdtcnt_clr_toggle <= ~wdtcnt_clr_toggle; // Synchronization wire wdtcnt_clr_sync; omsp_sync_cell sync_cell_wdtcnt_clr ( .data_out (wdtcnt_clr_sync), .data_in (wdtcnt_clr_toggle), .clk (wdt_clk), .rst (wdt_rst) ); // Edge detection reg wdtcnt_clr_sync_dly; always @ (posedge wdt_clk or posedge wdt_rst) if (wdt_rst) wdtcnt_clr_sync_dly <= 1'b0; else wdtcnt_clr_sync_dly <= wdtcnt_clr_sync; wire wdtqn_edge; wire wdtcnt_clr = (wdtcnt_clr_sync ^ wdtcnt_clr_sync_dly) | wdtqn_edge; // Watchog counter increment (synchronization) //---------------------------------------------- wire wdtcnt_incr; omsp_sync_cell sync_cell_wdtcnt_incr ( .data_out (wdtcnt_incr), .data_in (~wdtctl[7] & ~dbg_freeze), .clk (wdt_clk), .rst (wdt_rst) ); // Watchdog 16 bit counter //-------------------------- reg [15:0] wdtcnt; wire [15:0] wdtcnt_nxt = wdtcnt+16'h0001; `ifdef CLOCK_GATING wire wdtcnt_en = wdtcnt_clr | wdtcnt_incr; wire wdt_clk_cnt; omsp_clock_gate clock_gate_wdtcnt (.gclk(wdt_clk_cnt), .clk (wdt_clk), .enable(wdtcnt_en), .scan_enable(scan_enable)); `else wire wdt_clk_cnt = wdt_clk; `endif always @ (posedge wdt_clk_cnt or posedge wdt_rst) if (wdt_rst) wdtcnt <= 16'h0000; else if (wdtcnt_clr) wdtcnt <= 16'h0000; `ifdef CLOCK_GATING else wdtcnt <= wdtcnt_nxt; `else else if (wdtcnt_incr) wdtcnt <= wdtcnt_nxt; `endif // Local synchronizer for the wdtctl.WDTISx // configuration (note that we can live with // a full bus synchronizer as it won't hurt // if we get a wrong WDTISx value for a // single clock cycle) //-------------------------------------------- reg [1:0] wdtisx_s; reg [1:0] wdtisx_ss; always @ (posedge wdt_clk_cnt or posedge wdt_rst) if (wdt_rst) begin wdtisx_s <= 2'h0; wdtisx_ss <= 2'h0; end else begin wdtisx_s <= wdtctl[1:0]; wdtisx_ss <= wdtisx_s; end // Interval selection mux //-------------------------- reg wdtqn; always @(wdtisx_ss or wdtcnt_nxt) case(wdtisx_ss) 2'b00 : wdtqn = wdtcnt_nxt[15]; 2'b01 : wdtqn = wdtcnt_nxt[13]; 2'b10 : wdtqn = wdtcnt_nxt[9]; default: wdtqn = wdtcnt_nxt[6]; endcase // Watchdog event detection //----------------------------- // Interval end detection assign wdtqn_edge = (wdtqn & wdtcnt_incr); // Toggle bit for the transmition to the MCLK domain reg wdt_evt_toggle; always @ (posedge wdt_clk_cnt or posedge wdt_rst) if (wdt_rst) wdt_evt_toggle <= 1'b0; else if (wdtqn_edge) wdt_evt_toggle <= ~wdt_evt_toggle; // Synchronize in the MCLK domain wire wdt_evt_toggle_sync; omsp_sync_cell sync_cell_wdt_evt ( .data_out (wdt_evt_toggle_sync), .data_in (wdt_evt_toggle), .clk (mclk), .rst (puc_rst) ); // Delay for edge detection of the toggle bit reg wdt_evt_toggle_sync_dly; always @ (posedge mclk or posedge puc_rst) if (puc_rst) wdt_evt_toggle_sync_dly <= 1'b0; else wdt_evt_toggle_sync_dly <= wdt_evt_toggle_sync; wire wdtifg_evt = (wdt_evt_toggle_sync_dly ^ wdt_evt_toggle_sync) | wdtpw_error; // Watchdog wakeup generation //------------------------------------------------------------- // Clear wakeup when the watchdog flag is cleared (glitch free) reg wdtifg_clr_reg; wire wdtifg_clr; always @ (posedge mclk or posedge puc_rst) if (puc_rst) wdtifg_clr_reg <= 1'b1; else wdtifg_clr_reg <= wdtifg_clr; // Set wakeup when the watchdog event is detected (glitch free) reg wdtqn_edge_reg; always @ (posedge wdt_clk_cnt or posedge wdt_rst) if (wdt_rst) wdtqn_edge_reg <= 1'b0; else wdtqn_edge_reg <= wdtqn_edge; // Watchdog wakeup cell wire wdt_wkup_pre; omsp_wakeup_cell wakeup_cell_wdog ( .wkup_out (wdt_wkup_pre), // Wakup signal (asynchronous) .scan_clk (mclk), // Scan clock .scan_mode (scan_mode), // Scan mode .scan_rst (puc_rst), // Scan reset .wkup_clear (wdtifg_clr_reg), // Glitch free wakeup event clear .wkup_event (wdtqn_edge_reg) // Glitch free asynchronous wakeup event ); // When not in HOLD, the watchdog can generate a wakeup when: // - in interval mode (if interrupts are enabled) // - in reset mode (always) reg wdt_wkup_en; always @ (posedge mclk or posedge puc_rst) if (puc_rst) wdt_wkup_en <= 1'b0; else wdt_wkup_en <= ~wdtctl[7] & (~wdttmsel | (wdttmsel & wdtie)); // Make wakeup when not enabled wire wdt_wkup; omsp_and_gate and_wdt_wkup (.y(wdt_wkup), .a(wdt_wkup_pre), .b(wdt_wkup_en)); // Watchdog interrupt flag //------------------------------ reg wdtifg; wire wdtifg_set = wdtifg_evt | wdtifg_sw_set; assign wdtifg_clr = (wdtifg_irq_clr & wdttmsel) | wdtifg_sw_clr; always @ (posedge mclk or posedge por) if (por) wdtifg <= 1'b0; else if (wdtifg_set) wdtifg <= 1'b1; else if (wdtifg_clr) wdtifg <= 1'b0; // Watchdog interrupt generation //--------------------------------- wire wdt_irq = wdttmsel & wdtifg & wdtie; // Watchdog reset generation //----------------------------- reg wdt_reset; always @ (posedge mclk or posedge por) if (por) wdt_reset <= 1'b0; else wdt_reset <= wdtpw_error | (wdtifg_set & ~wdttmsel); //============================================================================= // 6) WATCHDOG TIMER (FPGA IMPLEMENTATION) //============================================================================= `else // Watchdog clock source selection //--------------------------------- wire clk_src_en = wdtctl[2] ? aclk_en : smclk_en; // Watchdog 16 bit counter //-------------------------- reg [15:0] wdtcnt; wire wdtifg_evt; wire wdtcnt_clr = (wdtctl_wr & per_din[3]) | wdtifg_evt; wire wdtcnt_incr = ~wdtctl[7] & clk_src_en & ~dbg_freeze; wire [15:0] wdtcnt_nxt = wdtcnt+16'h0001; always @ (posedge mclk or posedge puc_rst) if (puc_rst) wdtcnt <= 16'h0000; else if (wdtcnt_clr) wdtcnt <= 16'h0000; else if (wdtcnt_incr) wdtcnt <= wdtcnt_nxt; // Interval selection mux //-------------------------- reg wdtqn; always @(wdtctl or wdtcnt_nxt) case(wdtctl[1:0]) 2'b00 : wdtqn = wdtcnt_nxt[15]; 2'b01 : wdtqn = wdtcnt_nxt[13]; 2'b10 : wdtqn = wdtcnt_nxt[9]; default: wdtqn = wdtcnt_nxt[6]; endcase // Watchdog event detection //----------------------------- assign wdtifg_evt = (wdtqn & wdtcnt_incr) | wdtpw_error; // Watchdog interrupt flag //------------------------------ reg wdtifg; wire wdtifg_set = wdtifg_evt | wdtifg_sw_set; wire wdtifg_clr = (wdtifg_irq_clr & wdttmsel) | wdtifg_sw_clr; always @ (posedge mclk or posedge por) if (por) wdtifg <= 1'b0; else if (wdtifg_set) wdtifg <= 1'b1; else if (wdtifg_clr) wdtifg <= 1'b0; // Watchdog interrupt generation //--------------------------------- wire wdt_irq = wdttmsel & wdtifg & wdtie; wire wdt_wkup = 1'b0; // Watchdog reset generation //----------------------------- reg wdt_reset; always @ (posedge mclk or posedge por) if (por) wdt_reset <= 1'b0; else wdt_reset <= wdtpw_error | (wdtifg_set & ~wdttmsel); `endif endmodule // omsp_watchdog `ifdef OMSP_NO_INCLUDE `else `include "openMSP430_undefines.v" `endif