Subversion Repositories riscv_vhdl

/**

 * @file

 * @copyright  Copyright 2016 GNSS Sensor Ltd. All right reserved.

 * @author     Sergey Khabarov - sergeykhbr@gmail.com

 * @brief      CSR registers module.

 */

#include "csr.h"

#include "riscv-isa.h"

namespace debugger {

CsrRegs::CsrRegs(sc_module_name name_) : sc_module(name_) {

    SC_METHOD(comb);

    sensitive << i_nrst;

    sensitive << i_xret;

    sensitive << i_addr;

    sensitive << i_wena;

    sensitive << i_wdata;

    sensitive << i_break_mode;

    sensitive << i_breakpoint;

    sensitive << i_trap_ena;

    sensitive << i_trap_code;

    sensitive << i_trap_pc;

    sensitive << i_dport_ena;

    sensitive << i_dport_write;

    sensitive << i_dport_addr;

    sensitive << i_dport_wdata;

    sensitive << r.mtvec;

    sensitive << r.mscratch;

    sensitive << r.mbadaddr;

    sensitive << r.mode;

    sensitive << r.uie;

    sensitive << r.mie;

    sensitive << r.mpie;

    sensitive << r.mpp;

    sensitive << r.mepc;

    sensitive << r.trap_irq;

    sensitive << r.trap_code;

    SC_METHOD(registers);

    sensitive << i_clk.pos();

};

void CsrRegs::generateVCD(sc_trace_file *i_vcd, sc_trace_file *o_vcd) {

    if (o_vcd) {

        sc_trace(o_vcd, i_xret, "/top/proc0/csr0/i_xret");

        sc_trace(o_vcd, i_addr, "/top/proc0/csr0/i_addr");

        sc_trace(o_vcd, i_wena, "/top/proc0/csr0/i_wena");

        sc_trace(o_vcd, i_wdata, "/top/proc0/csr0/i_wdata");

        sc_trace(o_vcd, i_trap_ena, "/top/proc0/csr0/i_trap_ena");

        sc_trace(o_vcd, i_trap_code, "/top/proc0/csr0/i_trap_code");

        sc_trace(o_vcd, i_trap_pc, "/top/proc0/csr0/i_trap_pc");

        sc_trace(o_vcd, o_mode, "/top/proc0/csr0/o_mode");

        sc_trace(o_vcd, o_ie, "/top/proc0/csr0/o_ie");

        sc_trace(o_vcd, o_rdata, "/top/proc0/csr0/o_rdata");

        sc_trace(o_vcd, o_mtvec, "/top/proc0/csr0/o_mtvec");

        sc_trace(o_vcd, i_dport_ena, "/top/proc0/csr0/i_dport_ena");

        sc_trace(o_vcd, i_dport_write, "/top/proc0/csr0/i_dport_write");

        sc_trace(o_vcd, i_dport_addr, "/top/proc0/csr0/i_dport_addr");

        sc_trace(o_vcd, i_dport_wdata, "/top/proc0/csr0/i_dport_wdata");

        sc_trace(o_vcd, o_dport_rdata, "/top/proc0/csr0/o_dport_rdata");

    }

}

void CsrRegs::procedure_RegAccess(uint64_t iaddr, bool iwena,

                                 sc_uint<RISCV_ARCH> iwdata,

                                 RegistersType &ir, RegistersType *ov,

                                 sc_uint<RISCV_ARCH> *ordata) {

    *ordata = 0;

    switch (iaddr) {

    case CSR_misa:

        /** Base[XLEN-1:XLEN-2]

         *      1 = 32

         *      2 = 64

         *      3 = 128

         */

        (*ordata)(RISCV_ARCH-1, RISCV_ARCH-2) = 2;

        /** BitCharacterDescription

         * 0  A Atomic extension

         * 1  B Tentatively reserved for Bit operations extension

         * 2  C Compressed extension3DDouble-precision Foating-point extension

         * 4  E RV32E base ISA

         * 5  F Single-precision Foating-point extension

         * 6  G Additional standard extensions present

         * 7  H Hypervisor mode implemented

         * 8  I RV32I/64I/128I base ISA

         * 9  J Reserved

         * 10 K Reserved

         * 11 L Tentatively reserved for Decimal Floating-Point extension

         * 12 M Integer Multiply/Divide extension

         * 13 N User-level interrupts supported

         * 14 O Reserved

         * 15 P Tentatively reserved for Packed-SIMD extension

         * 16 Q Quad-precision Foating-point extension

         * 17 R Reserved

         * 18 S Supervisor mode implemented

         * 19 T Tentatively reserved for Transactional Memory extension

         * 20 U User mode implemented

         * 21 V Tentatively reserved for Vector extension

         * 22 W Reserved

         * 23 X Non-standard extensions present

         * 24 Y Reserved

         * 25 Z Reserve

         */

        //(*ordata)['A' - 'A'] = 1;

        (*ordata)['I' - 'A'] = 1;

        (*ordata)['M' - 'A'] = 1;

        (*ordata)['U' - 'A'] = 1;

        break;

    case CSR_mvendorid:

        break;

    case CSR_marchid:

        break;

    case CSR_mimplementationid:

        break;

    case CSR_mhartid:

        break;

    case CSR_uepc:// - User mode program counter

        break;

    case CSR_mstatus:// - Machine mode status register

        (*ordata)[0] = ir.uie;

        (*ordata)[3] = ir.mie;

        (*ordata)[7] = ir.mpie;

        (*ordata)(12, 11) = ir.mpp;

        if (iwena) {

            ov->uie = iwdata[0];

            ov->mie = iwdata[3];

            ov->mpie = iwdata[7];

            ov->mpp = iwdata(12, 11);

        }

        break;

    case CSR_medeleg:// - Machine exception delegation

        break;

    case CSR_mideleg:// - Machine itnerrupt delegation

        break;

    case CSR_mie:// - Machine interrupt enable bit

        break;

    case CSR_mtvec:

        (*ordata) = ir.mtvec;

        if (iwena) {

            ov->mtvec = iwdata;

        }

        break;

    case CSR_mtimecmp:// - Machine wall-clock timer compare value

        break;

    case CSR_mscratch:// - Machine scratch register

        (*ordata) = ir.mscratch;

        if (iwena) {

            ov->mscratch = iwdata;

        }

        break;

    case CSR_mepc:// - Machine program counter

        (*ordata) = ir.mepc;

        if (iwena) {

            ov->mepc = iwdata;

        }

        break;

    case CSR_mcause:// - Machine trap cause

        (*ordata) = 0;

        (*ordata)[63] = ir.trap_irq;

        (*ordata)(3, 0) = ir.trap_code;

        break;

    case CSR_mbadaddr:// - Machine bad address

        (*ordata) = ir.mbadaddr;

        break;

    case CSR_mip:// - Machine interrupt pending

        break;

    default:;

    }

}

void CsrRegs::comb() {

    sc_uint<RISCV_ARCH> wb_rdata = 0;

    sc_uint<RISCV_ARCH> wb_dport_rdata = 0;

    bool w_ie;

    bool w_dport_wena;

    v = r;

    w_dport_wena = i_dport_ena & i_dport_write;

    procedure_RegAccess(i_addr.read(), i_wena.read(), i_wdata.read(),

                        r, &v, &wb_rdata);

    procedure_RegAccess(i_dport_addr.read(), w_dport_wena,

                        i_dport_wdata.read(), r, &v, &wb_dport_rdata);

    if (i_addr.read() == CSR_mepc && i_xret.read()) {

        // Switch to previous mode

        v.mie = r.mpie;

        v.mpie = 1;

        v.mode = r.mpp;

        v.mpp = PRV_U;

    }

    if (i_trap_ena.read() && (i_break_mode.read() || !i_breakpoint.read())) {

        v.mie = 0;

        v.mpp = r.mode;

        v.mepc = i_trap_pc.read();

        v.mbadaddr = i_trap_pc.read();

        v.trap_code = i_trap_code.read()(3, 0);

        v.trap_irq = i_trap_code.read()[4];

        v.mode = PRV_M;

        switch (r.mode.read()) {

        case PRV_U:

            v.mpie = r.uie;

            break;

        case PRV_M:

            v.mpie = r.mie;

            break;

        default:;

        }

    }

    w_ie = 0;

    if ((r.mode.read() != PRV_M) || r.mie.read()) {

        w_ie = 1;

    }

    if (!i_nrst.read()) {

        v.mtvec = 0;

        v.mscratch = 0;

        v.mbadaddr = 0;

        v.mode = PRV_M;

        v.uie = 0;

        v.mie = 0;

        v.mpie = 0;

        v.mpp = 0;

        v.mepc = 0;

        v.trap_code = 0;

        v.trap_irq = 0;

    }

    o_rdata = wb_rdata;

    o_ie = w_ie;

    o_mode = r.mode;

    o_mtvec = r.mtvec.read()(BUS_ADDR_WIDTH - 1, 0);

    o_dport_rdata = wb_dport_rdata;

}

void CsrRegs::registers() {

    r = v;

}

}  // namespace debugger