5.24. Jump on Condition


Addr
Mode  Mnemonic          Format/Opcode
                           8      4     4             16
D     JC   C,LABEL      --------------------------------------
DX    JC   C,LABEL,RX   |  70  |  C  |  RX  |  |    LABEL    |
                        --------------------------------------
                           8      4     4             16
I     JCI  C,ADDR       --------------------------------------
IX    JCI  C,ADDR,RX    |  71  |  C  |  RX  |  |     ADDR    |
                        --------------------------------------

Description. This is a conditional jump instruction wherein the instruction sequence jumps to the Derived Address, DA, if a logical one results from the following operation:

  1. The 4-bit C field is bit-by-bit ANDed with the 4-bit condition status, CS

  2. The resulting 4-bits are ORed together

  3. or if C = 7 or C = F.



Otherwise, the next sequential instruction is executed.

Condition Codes.


C2     C16     Jump Condition                     Mnemonic
0000   0     NOP                                --   --   --
0001   1     less than (zero)                   LT   LZ   M
0010   2     equal to (zero)                    EQ   EZ   --
0011   3     less than or equal to (zero)       LE   LEZ  NP
0100   4     greater than (zero)                GT   GZ   P
0101   5     not equal to (zero)                NE   NZ   --
0110   6     greater than or equal to (zero)    GE   GEZ  NM
0111   7     unconditional                      --   --   --
1000   8     carry                              CY   --   --
1001   9     carry or LT                        --   --   --
1010   A     carry or EQ                        --   --   --
1011   B     carry or LE                        --   --   --
1100   C     carry or GT                        --   --   --
1101   D     carry or NE                        --   --   --
1110   E     carry or GE                        --   --   --
1111   F     unconditional                      --   --   --


Register Transfer Description.


(IC) <-- DA  if  C = 7, or
             if  C = F, or
             if (C 0 ^ CS0) v (C1 ^ CS 1) v (C2 ^ CS2) v (C3 ^ CS 3) = 1;



Registers Affected. IC (if jump is executed)