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[/] [ao486/] [trunk/] [rtl/] [ao486/] [commands/] [CMD_INC_DEC.txt] - Rev 2
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<defines>
`define CMD_INC_DEC #AUTOGEN_NEXT_CMD
`define CMDEX_INC_DEC_implicit 4'd0
`define CMDEX_INC_DEC_increment_implicit 4'd0
`define CMDEX_INC_DEC_decrement_implicit 4'd1
`define CMDEX_INC_DEC_modregrm 4'd2
`define CMDEX_INC_DEC_increment_modregrm 4'd2
`define CMDEX_INC_DEC_decrement_modregrm 4'd3
</defines>
<decode>
dec_ready_one && decoder[7:4] == 4'h4
`CMD_INC_DEC
SET(dec_cmdex, `CMDEX_INC_DEC_increment_implicit | { 3'd0, decoder[3] });
SET(consume_one);
</decode>
<decode>
dec_ready_modregrm_one && { decoder[7:1], 1'b0 } == 8'hFE && { decoder[13:12], 1'b0 } == 3'b000
prefix_group_1_lock && `DEC_MODREGRM_IS_MOD_11
`CMD_INC_DEC
SET(dec_cmdex, `CMDEX_INC_DEC_increment_modregrm | { 3'd0, decoder[11] });
IF(decoder[0] == 1'b0); SET(dec_is_8bit); ENDIF();
SET(consume_modregrm_one);
</decode>
<read>
IF(rd_cmd == `CMD_INC_DEC && { rd_cmdex[3:1], 1'b0 } == `CMDEX_INC_DEC_modregrm);
SET(rd_req_eflags);
SET(rd_src_is_1);
// dst: reg, src: reg
IF(rd_modregrm_mod == 2'b11);
IF(rd_mutex_busy_modregrm_rm); SET(rd_waiting);
ELSE();
// reg, reg
SET(rd_dst_is_rm);
SET(rd_req_rm);
ENDIF();
ENDIF();
// dst: memory, src: reg
IF(rd_modregrm_mod != 2'b11);
SET(rd_dst_is_memory);
SET(rd_req_memory);
IF(rd_mutex_busy_memory); SET(rd_waiting);
ELSE();
SET(read_rmw_virtual);
IF(~(read_for_rd_ready)); SET(rd_waiting); ENDIF();
ENDIF();
ENDIF();
ENDIF();
</read>
<read>
IF(rd_cmd == `CMD_INC_DEC && { rd_cmdex[3:1], 1'b0 } == `CMDEX_INC_DEC_implicit);
SET(rd_src_is_1);
SET(rd_dst_is_implicit_reg);
SET(rd_req_eflags);
SET(rd_req_implicit_reg);
// dst: implicit reg, src: imm
IF(rd_mutex_busy_implicit_reg); SET(rd_waiting); ENDIF();
ENDIF();
</read>
<execute>
IF(exe_cmd == `CMD_INC_DEC);
SET(exe_arith_index, (exe_cmdex[0] == `FALSE)? (`ARITH_VALID | `ARITH_ADD) : (`ARITH_VALID | `ARITH_SUB));
SET(exe_result, (exe_cmdex[0] == `FALSE)? exe_arith_add[31:0] : exe_arith_sub[31:0]);
ENDIF();
</execute>
<write>
IF(wr_cmd == `CMD_INC_DEC);
IF(wr_dst_is_memory && ~(write_for_wr_ready)); SET(wr_waiting); ENDIF();
SET(write_rmw_virtual, wr_dst_is_memory);
SET(write_regrm, wr_dst_is_implicit_reg || wr_dst_is_rm);
// no carry flag
SAVE(zflag, zflag_result);
SAVE(sflag, sflag_result);
SAVE(pflag, pflag_result);
SAVE(aflag, aflag_arith);
SAVE(oflag, oflag_arith);
ENDIF();
</write>