mc68ec060 Freescale Semiconductor, Inc, mc68ec060 Datasheet - Page 132

• Manufacturer Part Number: mc68ec060
• Description: Mc68060 Superscalar 68k Microprocessor Including The Lc060 And Ec060
• Manufacturer: Freescale Semiconductor, Inc

Floating-Point Unit
handled in this manner. If the destination data format is extended and there is a difference
between the infinitely precise intermediate result and the round-to-nearest result, the rela-
tive difference is 2
significant bit’s value and is the worst case error that can be introduced when using the RN
6-14
Rounded-to-Nearest
RN
Intermediate
ROUND AND STICKY = 0
Result
ROUND OR STICKY = 1
GUARD AND LSB = 1,
ADD 1 TO
GUARD = 1
–64
LSB
OR
(the value of the guard bit). This error is equal to one-half of the least
Figure 6-9. Rounding Algorithm Flowchart
ADD 1 TO EXPONENT
SHIFT MANTISSA
RIGHT 1 BIT,
Integer
POS
INTERMEDIATE
x
x
RM
RESULT
M68060 USER’S MANUAL
NEG POS
ADD 1 TO
OVERFLOW = 1
LSB
INTERMEDIATE
63-Bit Fraction
SELECT ROUNDING MODE
RP
RESULT
xxx…x00
xxx…x00
INEX2 1
ROUND 0
GUARD 0
STICKY 0
NEG
ENTRY
EXIT
AND STICKY ARE
GUARD, ROUND,
AND STICKY BITS = 0
CHOPPED
RZ
GUARD, ROUND,
Guard
1
0
Round
EXACT RESULT
0
0
EXIT
Sticky
MOTOROLA
0
0