Computer Hardware User's Guide

Add Floating Point, 3-Operand ADDF3
13-53 Assembly Language Instructions
Syntax ADDF3 src2 , src1 , dst
Operation src1 + src2 → dst
Operands src1 3-operand addressing modes (T):
0 0 register (R n 1, 0 ≤ n 1 ≤ 7)
0 1 indirect (
disp = 0, 1, IR0, IR1)
1 0 register (R n 1, 0 ≤ n 1 ≤ 7)
1 1 indirect ( disp = 0, 1, IR0, IR1)
src2 3-operand addressing modes (T):
0 0 register (R
n 2, 0 ≤ n 2 ≤ 7)
0 1 register (R n 2, 0 ≤ n 2 ≤ 7)
1 0 indirect ( disp = 0, 1, IR0, IR1)
1 1 indirect ( disp = 0, 1, IR0, IR1)
dst register (R n , 0 ≤ n ≤ 7)
Opcode
31 24
23
16 8 7 015
00100 1 T
src 2 src 10
dst
0 0
Description The sum of the src1 and src2 operands is loaded into the dst register. The src1,
src2, and dst operands are assumed to be floating-point numbers.
Cycles 1
Status Bits These condition flags are modified only if the destination register is R7–R0.
LUF 1 if a floating-point underflow occurs; unchanged otherwise
LV 1 if a floating-point overflow occurs; unchanged otherwise
UF 1 if a floating-point underflow occurs; 0 otherwise
N 1 if a negative result is generated; 0 otherwise
Z 1 if a 0 result is generated; 0 otherwise
V 1 if a floating-point overflow occurs; 0 otherwise
C Unaffected
OVM Operation is not affected by OVM bit value.
Mode Bit