5.94. Floating Point Compare


Addr
Mode  Mnemonic          Format/Opcode
                           8      4      4
                        ----------------------
R     FCR    RA,RB      |  F9  |  RA  |  RB  |
                        ----------------------
                           4   2   2     8          12<=BR<=15
                        ----------------------
B     FCB    BR,DSPL    | 3 | 3 | BR' | DSPL |      BR'=BR-12
                        ----------------------      RA=R0
                           4   2   2     4   4      12<=BR<=15
                        ------------------------
BX    FCBX   BR,RX      | 4 | 0 | BR' | D | RX |    BR'=BR-12
                        ------------------------    RA=R0
                            4      8      8           16
D     FC     RA,ADDR    --------------------------------------
DX    FC     RA,ADDR,RX |  F8  |  RA  |  RX  |  |    ADDR    |
                        --------------------------------------

Description. The floating point number in registers RA and RA+1 is compared to the floating point Derived Operand, DO. Then, the Condition Status, CS, is set based on whether the contents of RA, RA+1 is less than, equal to, or greater than the DO. The contents of RA and RA+1 are unchanged.

Note: This instruction does not cause an overflow to occur.

Register Transfer Description.

(RA, RA+1) : DO;
(CS) <-- 0010  if (RA,RA+1) = DO;
(CS) <-- 0001  if (RA,RA+1) < DO;
(CS) <-- 0100  if (RA,RA+1) >= DO;

Registers Affected. CS