/*

  Copyright (C) 2008 Martin Furter <mf@rola.ch>

  This file is part of wbavr.

  wbavr is free software/hardware; 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 2, or (at your option)
  any later version.

  wbavr 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 wbavr; see the file COPYING.  If not, write to
  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

==============================================================================*/
/*

wbavr_consts: Constants used in the other files.

*/

// no operation
`define ALU_NOP     5'b00000

// one input, one output
`define ALU_ASR     5'b00001
`define ALU_LSR     5'b00010
`define ALU_ROR     5'b00011
`define ALU_SWAP    5'b00100

// two inputs, one output
`define ALU_ADD     5'b01000
// same as ADD except that H and C aren't changed (set data_1_i to 1)
`define ALU_INC     5'b01001
`define ALU_ADC     5'b01010
`define ALU_SUB     5'b01100
// same as SUB except that H and C aren't changed (set data_1_i to 1)
`define ALU_DEC     5'b01101
// same as SUB except that H isn't changed and C is always 1 (data_0=0xFF)
`define ALU_COM     5'b01110
`define ALU_SBC     5'b01111
`define ALU_AND     5'b10000
`define ALU_EOR     5'b10001
`define ALU_OR      5'b10010

// three inputs, two outputs
`define ALU_ADDW    5'b10100
`define ALU_SUBW    5'b10101

// two inputs, two outputs
`define ALU_FMUL    5'b11000
`define ALU_FMULS   5'b11011
`define ALU_FMULSU  5'b11001
`define ALU_MUL     5'b11000
`define ALU_MULS    5'b11111
`define ALU_MULSU   5'b11101

// data_2_i[2:0] selects the bit
// data_1_i[0] specifies the new value for the bit
// data_0_i is copied to data_0_o with the specified bit replaced
// T contains the old value of the bit
`define ALU_BITOP   5'b10111

// flag bit numbers
`define FLAG_C_IDX  0
`define FLAG_Z_IDX  1
`define FLAG_N_IDX  2
`define FLAG_V_IDX  3
`define FLAG_S_IDX  4
`define FLAG_H_IDX  5
`define FLAG_T_IDX  6
`define FLAG_I_IDX  7

// control register bit numbers
`define CTRL_SELFPRGEN      0
`define CTRL_PGWRT          2

`define ALU_I0_SEL_REG0     0
`define ALU_I0_SEL_FLAGS    1
`define ALU_I0_SEL_DATA     2
`define ALU_I0_SEL_CONST1   3
`define ALU_I0_SEL_SP_LO    4
`define ALU_I0_SEL_SP_HI    5
`define ALU_I0_SEL_CTRL     6

`define ALU_I1_SEL_REG1     0
`define ALU_I1_SEL_CONST1   1
`define ALU_I1_SEL_TFLAG    2
`define ALU_I1_SEL_CODE     3

`define CADR_SEL_PC         0
`define CADR_SEL_TMPREG     1
`define CADR_SEL_GPREG      2

`define DADR_SEL_OPCODE     0
`define DADR_SEL_TMPREG     1
`define DADR_SEL_SP_DEC     2
`define DADR_SEL_SP_INC     3

`define DDAT_SEL_REG0       0
`define DDAT_SEL_TMP_LO     1
`define DDAT_SEL_PC_LO      2
`define DDAT_SEL_PC_HI      3

`define FLAG_SEL_PREV       0
`define FLAG_SEL_ALU        1
`define FLAG_SEL_O0         2
`define FLAG_SEL_CHG_I      3

`define TMP_LO_SEL_PREV     0
`define TMP_LO_SEL_ALU_O0   1
`define TMP_LO_SEL_CODE_RD  2

`define TMP_HI_SEL_PREV     0
`define TMP_HI_SEL_ALU_O1   1
`define TMP_HI_SEL_CODE_RD  2
`define TMP_HI_SEL_DATA_RD  3

`define PC_SEL_PREV         0
`define PC_SEL_INC          1
`define PC_SEL_ABSADDR      2
`define PC_SEL_RELADDR      3
`define PC_SEL_CODE         4
`define PC_SEL_REG          5
`define PC_SEL_THI_DLO      6

`define SP_SEL_PREV         0
`define SP_SEL_INCDEC       1
`define SP_SEL_WR_LO        2
`define SP_SEL_WR_HI        3

`define SKIP_SEL_NONE       0
`define SKIP_SEL_Z_SET      1
`define SKIP_SEL_T_CLR      2
`define SKIP_SEL_T_SET      3