Computational Units
2 – 35
2
If the upper half of the input contains all sign bits, the SE register value is
determined by the second derive exponent operation as shown below.
1. Detect Exponent, Modifier = HI
First Input:
11111111 11111111
(Must be upper half)
SE set to:
-15
2. Detect Exponent, Modifier = LO
Second Input:
11110110 11010100
SE now set to:
-19
3. Normalize, Modifier=HI, No [SR OR], SE = –19 (negated)
First Input:
11111111 11111111
SR:
00000000 00000000 00000000 00000000
All values of SE less than –15 (resulting in a shift of +16 or more) upshift
the input completely off scale.
4. Normalize, Modifier=LO, [SR OR], SE = –19 (negated)
Second Input:
11110110 11010100
SR:
10110110 10100 000 00000000 00000000