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 .

// LOOP

.at 0xe2;

    width W8, read_immed, jmp loop;

.auto_address;

loop:

    ra_sel CX;

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

        rd_sel_source MICROCODE_RD_SEL, rd_sel CX,

        rb_cl;

    jmp_rb_zero loop_not_taken;

    a_sel IP, b_sel IMMEDIATE, alu_op ADD, load_ip, next_instruction;

loop_not_taken:

    next_instruction;

// LOOPE

.at 0xe1;

    width W8, read_immed, jmp loope;

.auto_address;

loope:

    ra_sel CX;

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

        rd_sel_source MICROCODE_RD_SEL, rd_sel CX, rb_cl,

        jmp_if_zero loope_maybe_taken;

    jmp loop_not_taken;

loope_maybe_taken:

    jmp_rb_zero loop_not_taken;

    a_sel IP, b_sel IMMEDIATE, alu_op ADD, load_ip, next_instruction;

// LOOPNE

.at 0xe0;

    width W8, read_immed, jmp loopne;

.auto_address;

loopne:

    ra_sel CX;

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

        rd_sel_source MICROCODE_RD_SEL, rd_sel CX, rb_cl,

        jmp_if_zero loop_not_taken;

    jmp_rb_zero loop_not_taken;

loopne_taken:

    a_sel IP, b_sel IMMEDIATE, alu_op ADD, load_ip, next_instruction;