General Purpose Arithmetic And Cpu Control Groups

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Mnemonic        Symbolic            Flags (bit 7-0)   Instruction         Number      Number of   Number of   Comments
                operation           S Z . H . V N C   opcode              of bytes    M cycles    T states
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DAA             Converts accum.     ? ? X ? X P * ?   00 100 111 (27h)    1           1           4           Decimal
                contents into                                                                                 adjust
                packed BCD format                                                                             accumulator

CPL             A <- NOT A          * * X 1 X * 1 *   00 101 111 (2Fh)    1           1           4           Complement
                (1. complement)                                                                               accumulator

NEG             A <- 0 - A          ? ? X ? X V 1 ?   11 101 101 (EDh)    2           2           8           Negate
                (2. complement)                       01 000 100 (44h)                                        accumulator

CCF             CY <- NOT CY        * * X X X * 0 ?   00 111 111 (3Fh)    1           1           4           Complement
                                                                                                              Carry flag

SCF             CY <- 1             * * X 0 X * 0 1   00 110 111 (37h)    1           1           4           Set Carry
                                                                                                              flag
NOP             No operation        * * X * X * * *   00 000 000          1           1           4
HALT            CPU halted          * * X * X * * *   01 110 110 (76h)    1           1           4
DI              IFF <- 0            * * X * X * * *   11 110 011 (F3h)    1           1           4
EI              IFF <- 1            * * X * X * * *   11 111 011 (FBh)    1           1           4
IM 0            Set int. mode 0     * * X * X * * *   11 101 101 (EDh)    2           2           8
                                                      01 000 110 (46h)
IM 1            Set int. mode 1     * * X * X * * *   11 101 101 (EDh)    2           2           8
                                                      01 010 110 (56h)
IM 2            Set int. mode 2     * * X * X * * *   11 101 101 (EDh)    2           2           8
                                                      01 011 110 (5Eh)


IFF = Interrupt enable flip-flop