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[/] [ao486/] [trunk/] [rtl/] [ao486/] [commands/] [CMD_MOVSX_MOVZX.txt] - Rev 8

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<defines>
`define CMD_MOVZX       #AUTOGEN_NEXT_CMD

`define CMD_MOVSX       #AUTOGEN_NEXT_CMD
</defines>

<decode>
dec_ready_2byte_modregrm && { decoder[7:1], 1'b0 } == 8'hB6
`CMD_MOVZX
IF(decoder[0] == 1'b0); SET(dec_is_8bit); ENDIF();
SET(consume_modregrm_one);
</decode>

<decode>
dec_ready_2byte_modregrm && { decoder[7:1], 1'b0 } == 8'hBE
`CMD_MOVSX
IF(decoder[0] == 1'b0); SET(dec_is_8bit); ENDIF();
SET(consume_modregrm_one);
</decode>

<read>
IF(rd_cmd == `CMD_MOVSX || rd_cmd == `CMD_MOVZX);
        
    SET(rd_dst_is_reg);
    
    SET(rd_req_reg_not_8bit);

    // dst: reg, src: reg
    IF(rd_modregrm_mod == 2'b11);
            
        SET(rd_src_is_rm);
    
        IF(rd_mutex_busy_modregrm_rm); SET(rd_waiting); ENDIF();
    ENDIF();

    // dst: memory, src: reg
    IF(rd_modregrm_mod != 2'b11);
        
        SET(read_length_word);
    
        SET(rd_src_is_memory);
    
        IF(rd_mutex_busy_memory); SET(rd_waiting);
        ELSE();
            SET(read_virtual);

            IF(~(read_for_rd_ready)); SET(rd_waiting); ENDIF();
        ENDIF();
    ENDIF();
ENDIF();
</read>

<execute>
IF(exe_cmd == `CMD_MOVSX || exe_cmd == `CMD_MOVZX);
    
    SET(exe_result, (exe_cmd == `CMD_MOVSX && exe_is_8bit)?     { {24{src[7]}},  src[7:0] } :
                    (exe_cmd == `CMD_MOVSX)?                    { {16{src[15]}}, src[15:0] } :
                    (exe_cmd == `CMD_MOVZX && exe_is_8bit)?     { 24'd0, src[7:0] } :
                                                                { 16'd0, src[15:0] });
    
    SET(exe_is_8bit_clear, exe_is_8bit);
    
ENDIF();
</execute>

<write>
IF(wr_cmd == `CMD_MOVSX || wr_cmd == `CMD_MOVZX);
    SET(write_regrm);
ENDIF();
</write>

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