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 <http://www.gnu.org/licenses/>.

// 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;