5.56. Increment Memory by a Positive Integer

Addr
Mode  Mnemonic          Format/Opcode
                            8      4       4          16
D     INCM   N,ADDR     ---------------------------------------
DX    INCM   N,ADDR,RX  |  A3  |  N-1  |  RX  |  |    ADDR    |
                        ---------------------------------------

Description. The contents of the memory location specified by the Derived Address, DA, is incremented by N, where N is an integer, 1 <= N <= 16. This instruction adds a positive constant to memory. The condition status, CS, is set based on the results of the addition and carry. A fixed point overflow occurs if the operand in memory is positive and the result is negative. The memory location specified is updated to contain the result of the addition process even if a fixed point overflow occurs.

Register Transfer Description.

[DA]² <-- [DA]¹ + N, where 1 <= N <= 16;
PI₄ <-- 1, if [DA]² < 0 < [DA] ¹;
(CS) <-- 0010  if  carry = 0 and [DA] = 0;
(CS) <-- 0001  if  carry = 0 and [DA] < 0;
(CS) <-- 0100  if  carry = 0 and [DA] > 0;
(CS) <-- 1010  if  carry = 1 and [DA] = 0;
(CS) <-- 1001  if  carry = 1 and [DA] < 0;
(CS) <-- 1100  if  carry = 1 and [DA] > 0;

Registers Affected. CS, PI