zpu_pkg.py

#
# This file contains the definitions used in the ZPU implementation
#
 
from myhdl import enum
 
# @TODO This should really be shared with the Simulation Table!  But the
#       seperate (cross) verification of the different tables will be useful
 
# Opcode decode constants
# Note:  These are the basic opcodes, always implemented using hardware
OPCODE_IM        =  int('10000000', 2)
OPCODE_STORESP   =  int('01000000', 2)
OPCODE_LOADSP    =  int('01100000', 2)
OPCODE_EMULATE   =  int('00100000', 2)
OPCODE_ADDSP     =  int('00010000', 2)
OPCODE_SHORT     =  int('00000000', 2)
 
OPCODE_BREAK     =  int('00000000', 2)
OPCODE_SHIFTLEFT =  int('00000001', 2)
OPCODE_PUSHSP    =  int('00000010', 2)
OPCODE_PUSHINT   =  int('00000011', 2)
 
OPCODE_POPPC     =  int('00000100', 2)
OPCODE_ADD       =  int('00000101', 2)
OPCODE_AND       =  int('00000110', 2)
OPCODE_OR        =  int('00000111', 2)
 
OPCODE_LOAD      =  int('00001000', 2)
OPCODE_NOT       =  int('00001001', 2)
OPCODE_FLIP      =  int('00001010', 2)
OPCODE_NOP       =  int('00001011', 2)
 
OPCODE_STORE     =  int('00001100', 2)
OPCODE_POPSP     =  int('00001101', 2)
OPCODE_COMPARE   =  int('00001110', 2)
OPCODE_POPINT    =  int('00001111', 2)
 
#  The following instructions are emulated in the small version and
#  implmented as hardware in the full version.
#  The constants correspond to the "emulated" instruction number
OPCODE_EQ        =  46
OPCODE_LOADB     =  51
OPCODE_NEQBRANCH =  56
OPCODE_PUSHSPADD =  61
 
OPCODE_LESSTHAN  =  36
OPCODE_ULESSTHAN =  38
OPCODE_MULT      =  41
OPCODE_STOREB    =  52
OPCODE_CALLPCREL =  63
OPCODE_SUB       =  49
 
OPCODE_LESSTHAN_OREQUAL =  37
OPCODE_ULESSTHANOREQUAL =  39
OPCODE_CALL             =  45
OPCODE_POPPCREL         =  57
OPCODE_LSHIFTRIGHT      =  42
 
#  The following opcodes are always emulated
OPCODE_LOADH       =  34
OPCODE_STOREH      =  35
OPCODE_ASHIFTLEFT  =  43
OPCODE_ASHIFTRIGHT =  44
OPCODE_NEQ         =  47
OPCODE_NEG         =  48
OPCDOE_XOR         =  50
OPCODE_DIV         =  53
OPCODE_MOD         =  54
OPCODE_EQBRANCH    =  55
OPCODE_CONFIG      =  58
OPCODE_PUSHPC      =  59
 
# Enumeration for the CPU states
state_t = enum('FETCH', 'WRITE_IO_DONE', 'EXECUTE', 'ADD', 'OR', 'AND', 'STORE',
               'READ_IO', 'WRITE_IO', 'FETCH_NEXT', 'ADD_SP', 'DECODE', 'RESYNC')
 
# Decode Opcode
decode_t = enum('DEC_NOP', 'DEC_IM', 'DEC_LOAD_SP', 'DEC_STORE_SP', 'DEC_ADD_SP',
                'DEC_EMULATE', 'DEC_BREAK', 'DEC_PUSH_SP', 'DEC_POP_PC', 'DEC_ADD',
                'DEC_OR', 'DEC_AND', 'DEC_LOAD', 'DEC_NOT', 'DEC_FLIP', 'DEC_STORE',
                'DEC_POP_SP', 'DEC_INTERRUPT')