//---------------------------------------------------------------------------- // 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_sfr.v // // *Module Description: // Processor Special function register // Non-Maskable Interrupt generation // // *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_sfr ( // OUTPUTs cpu_id, // CPU ID nmi_pnd, // NMI Pending nmi_wkup, // NMI Wakeup per_dout, // Peripheral data output wdtie, // Watchdog-timer interrupt enable wdtifg_sw_clr, // Watchdog-timer interrupt flag software clear wdtifg_sw_set, // Watchdog-timer interrupt flag software set // INPUTs mclk, // Main system clock nmi, // Non-maskable interrupt (asynchronous) nmi_acc, // Non-Maskable interrupt request accepted per_addr, // Peripheral address per_din, // Peripheral data input per_en, // Peripheral enable (high active) per_we, // Peripheral write enable (high active) puc_rst, // Main system reset scan_mode, // Scan mode wdtifg, // Watchdog-timer interrupt flag wdtnmies // Watchdog-timer NMI edge selection ); // OUTPUTs //========= output [31:0] cpu_id; // CPU ID output nmi_pnd; // NMI Pending output nmi_wkup; // NMI Wakeup output [15:0] per_dout; // Peripheral data output output wdtie; // Watchdog-timer interrupt enable output wdtifg_sw_clr;// Watchdog-timer interrupt flag software clear output wdtifg_sw_set;// Watchdog-timer interrupt flag software set // INPUTs //========= input mclk; // Main system clock input nmi; // Non-maskable interrupt (asynchronous) input nmi_acc; // Non-Maskable interrupt request accepted 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 puc_rst; // Main system reset input scan_mode; // Scan mode input wdtifg; // Watchdog-timer interrupt flag input wdtnmies; // Watchdog-timer NMI edge selection //============================================================================= // 1) PARAMETER DECLARATION //============================================================================= // Register base address (must be aligned to decoder bit width) parameter [14:0] BASE_ADDR = 15'h0000; // Decoder bit width (defines how many bits are considered for address decoding) parameter DEC_WD = 3; // Register addresses offset parameter [DEC_WD-1:0] IE1 = 'h0, IFG1 = 'h2, CPU_ID_LO = 'h4, CPU_ID_HI = 'h6; // 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] IE1_D = (BASE_REG << IE1), IFG1_D = (BASE_REG << IFG1), CPU_ID_LO_D = (BASE_REG << CPU_ID_LO), CPU_ID_HI_D = (BASE_REG << CPU_ID_HI); //============================================================================ // 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 = (IE1_D & {DEC_SZ{(reg_addr==(IE1 >>1))}}) | (IFG1_D & {DEC_SZ{(reg_addr==(IFG1 >>1))}}) | (CPU_ID_LO_D & {DEC_SZ{(reg_addr==(CPU_ID_LO >>1))}}) | (CPU_ID_HI_D & {DEC_SZ{(reg_addr==(CPU_ID_HI >>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 //============================================================================ // IE1 Register //-------------- wire [7:0] ie1; wire ie1_wr = IE1[0] ? reg_hi_wr[IE1] : reg_lo_wr[IE1]; wire [7:0] ie1_nxt = IE1[0] ? per_din[15:8] : per_din[7:0]; `ifdef NMI reg nmie; always @ (posedge mclk or posedge puc_rst) if (puc_rst) nmie <= 1'b0; else if (nmi_acc) nmie <= 1'b0; else if (ie1_wr) nmie <= ie1_nxt[4]; `else wire nmie = 1'b0; `endif `ifdef WATCHDOG reg wdtie; always @ (posedge mclk or posedge puc_rst) if (puc_rst) wdtie <= 1'b0; else if (ie1_wr) wdtie <= ie1_nxt[0]; `else wire wdtie = 1'b0; `endif assign ie1 = {3'b000, nmie, 3'b000, wdtie}; // IFG1 Register //--------------- wire [7:0] ifg1; wire ifg1_wr = IFG1[0] ? reg_hi_wr[IFG1] : reg_lo_wr[IFG1]; wire [7:0] ifg1_nxt = IFG1[0] ? per_din[15:8] : per_din[7:0]; `ifdef NMI reg nmiifg; wire nmi_edge; always @ (posedge mclk or posedge puc_rst) if (puc_rst) nmiifg <= 1'b0; else if (nmi_edge) nmiifg <= 1'b1; else if (ifg1_wr) nmiifg <= ifg1_nxt[4]; `else wire nmiifg = 1'b0; `endif `ifdef WATCHDOG assign wdtifg_sw_clr = ifg1_wr & ~ifg1_nxt[0]; assign wdtifg_sw_set = ifg1_wr & ifg1_nxt[0]; `else assign wdtifg_sw_clr = 1'b0; assign wdtifg_sw_set = 1'b0; `endif assign ifg1 = {3'b000, nmiifg, 3'b000, wdtifg}; // CPU_ID Register (READ ONLY) //----------------------------- // ------------------------------------------------------------------- // CPU_ID_LO: | 15 14 13 12 11 10 9 | 8 7 6 5 4 | 3 | 2 1 0 | // |----------------------------+-----------------+------+-------------| // | PER_SPACE | USER_VERSION | ASIC | CPU_VERSION | // -------------------------------------------------------------------- // CPU_ID_HI: | 15 14 13 12 11 10 | 9 8 7 6 5 4 3 2 1 | 0 | // |----------------------------+-------------------------------+------| // | PMEM_SIZE | DMEM_SIZE | MPY | // ------------------------------------------------------------------- wire [2:0] cpu_version = `CPU_VERSION; `ifdef ASIC wire cpu_asic = 1'b1; `else wire cpu_asic = 1'b0; `endif wire [4:0] user_version = `USER_VERSION; wire [6:0] per_space = (`PER_SIZE >> 9); // cpu_id_per * 512 = peripheral space size `ifdef MULTIPLIER wire mpy_info = 1'b1; `else wire mpy_info = 1'b0; `endif wire [8:0] dmem_size = (`DMEM_SIZE >> 7); // cpu_id_dmem * 128 = data memory size wire [5:0] pmem_size = (`PMEM_SIZE >> 10); // cpu_id_pmem * 1024 = program memory size assign cpu_id = {pmem_size, dmem_size, mpy_info, per_space, user_version, cpu_asic, cpu_version}; //============================================================================ // 4) DATA OUTPUT GENERATION //============================================================================ // Data output mux wire [15:0] ie1_rd = {8'h00, (ie1 & {8{reg_rd[IE1]}})} << (8 & {4{IE1[0]}}); wire [15:0] ifg1_rd = {8'h00, (ifg1 & {8{reg_rd[IFG1]}})} << (8 & {4{IFG1[0]}}); wire [15:0] cpu_id_lo_rd = cpu_id[15:0] & {16{reg_rd[CPU_ID_LO]}}; wire [15:0] cpu_id_hi_rd = cpu_id[31:16] & {16{reg_rd[CPU_ID_HI]}}; wire [15:0] per_dout = ie1_rd | ifg1_rd | cpu_id_lo_rd | cpu_id_hi_rd; //============================================================================= // 5) NMI GENERATION //============================================================================= // NOTE THAT THE NMI INPUT IS ASSUMED TO BE NON-GLITCHY `ifdef NMI //----------------------------------- // Edge selection //----------------------------------- wire nmi_pol = nmi ^ wdtnmies; //----------------------------------- // Pulse capture and synchronization //----------------------------------- `ifdef SYNC_NMI `ifdef ASIC // Glitch free reset for the event capture reg nmi_capture_rst; always @(posedge mclk or posedge puc_rst) if (puc_rst) nmi_capture_rst <= 1'b1; else nmi_capture_rst <= ifg1_wr & ~ifg1_nxt[4]; // NMI event capture wire nmi_capture; omsp_wakeup_cell wakeup_cell_nmi ( .wkup_out (nmi_capture), // Wakup signal (asynchronous) .scan_clk (mclk), // Scan clock .scan_mode (scan_mode), // Scan mode .scan_rst (puc_rst), // Scan reset .wkup_clear (nmi_capture_rst), // Glitch free wakeup event clear .wkup_event (nmi_pol) // Glitch free asynchronous wakeup event ); `else wire nmi_capture = nmi_pol; `endif // Synchronization wire nmi_s; omsp_sync_cell sync_cell_nmi ( .data_out (nmi_s), .data_in (nmi_capture), .clk (mclk), .rst (puc_rst) ); `else wire nmi_capture = nmi_pol; wire nmi_s = nmi_pol; `endif //----------------------------------- // NMI Pending flag //----------------------------------- // Delay reg nmi_dly; always @ (posedge mclk or posedge puc_rst) if (puc_rst) nmi_dly <= 1'b0; else nmi_dly <= nmi_s; // Edge detection assign nmi_edge = ~nmi_dly & nmi_s; // NMI pending wire nmi_pnd = nmiifg & nmie; // NMI wakeup `ifdef ASIC wire nmi_wkup; omsp_and_gate and_nmi_wkup (.y(nmi_wkup), .a(nmi_capture ^ nmi_dly), .b(nmie)); `else wire nmi_wkup = 1'b0; `endif `else wire nmi_pnd = 1'b0; wire nmi_wkup = 1'b0; `endif endmodule // omsp_sfr `ifdef OMSP_NO_INCLUDE `else `include "openMSP430_undefines.v" `endif