Subversion Repositories s80186

// Copyright Jamie Iles, 2017

//

// This file is part of s80x86.

//

// s80x86 is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// s80x86 is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with s80x86.  If not, see .

.at 0xaa;

    width W8, ra_sel AL, jmp stosb;

.auto_address;

stosb:

    width W8, a_sel RA, alu_op SELA, mdr_write;

    ra_sel DI, rb_cl, jmp_if_not_rep stosb_no_rep;

stosb_rep_loop:

    ra_sel CX, jmp_rb_zero stosb_done;

    ra_sel DI, a_sel RA, b_sel IMMEDIATE, immediate 0x1, alu_op SUB,

        rd_sel_source MICROCODE_RD_SEL, rd_sel CX;

stosb_no_rep:

    ra_sel DI, a_sel RA, alu_op SELA, mar_wr_sel Q, mar_write;

    a_sel RA, b_sel IMMEDIATE, immediate 0x1, alu_op NEXT,

        rd_sel_source MICROCODE_RD_SEL, rd_sel DI;

    width W8, ra_sel AL;

    width W8, alu_op SELA, mdr_write, segment ES, segment_force;

    width W8, segment ES, segment_force, mem_write, jmp_if_not_rep stosb_done;

    rb_cl, ext_int_yield, jmp stosb_rep_loop;

stosb_done:

    next_instruction;

.at 0xab;

    ra_sel AX, jmp stosw;

.auto_address;

stosw:

    a_sel RA, alu_op SELA, mdr_write,

        ra_sel DI, rb_cl, jmp_if_not_rep stosw_no_rep;

stosw_rep_loop:

    ra_sel CX, jmp_rb_zero stosw_done;

    ra_sel DI, a_sel RA, b_sel IMMEDIATE, immediate 0x1, alu_op SUB,

        rd_sel_source MICROCODE_RD_SEL, rd_sel CX;

stosw_no_rep:

    ra_sel DI, a_sel RA, alu_op SELA, mar_wr_sel Q, mar_write;

    a_sel RA, b_sel IMMEDIATE, immediate 0x2, alu_op NEXT,

        rd_sel_source MICROCODE_RD_SEL, rd_sel DI, segment ES, segment_force;

    segment ES, segment_force, mem_write, jmp_if_not_rep stosw_done;

    rb_cl, ext_int_yield, jmp stosw_rep_loop;

stosw_done:

    next_instruction;