MC68EC000EI16 Freescale Semiconductor, MC68EC000EI16 Datasheet - Page 97

• Manufacturer Part Number: MC68EC000EI16
• Description: IC MPU 32BIT 16MHZ 68-PLCC
• Manufacturer: Freescale Semiconductor

Specifications of MC68EC000EI16

• Processor Type: M680x0 32-Bit
• Speed: 16MHz
• Voltage: 3.3V, 5V
• Mounting Type: Surface Mount
• Package / Case: 68-PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

Instruction Set Summary
The three additional bits beyond the extended-precision format, the difference between the
intermediate result’s 67-bit mantissa and the storing result’s 64-bit mantissa, allow the FPU
to perform all calculations as though it were performing calculations using a float engine with
infinite bit prec The result is always correct for the specified destination’s data format before
performing rounding (unless an overflow or underflow error occurs). The specified rounding
operation then produces a number that is as close as possible to the infinitely precise
3-26
RN
ROUND AND STICKY = 0
ROUND OR STICKY = 1
GUARD AND LSB = 1,
ADD 1 TO
GUARD = 1
LSB
M68000 FAMILY PROGRAMMER’S REFERENCE MANUAL
OR
Figure 3-2. Rounding Algorithm Flowchart
ADD 1 TO EXPONENT
SHIFT MANTISSA
RIGHT 1 BIT,
POS
INTERMEDIATE
RM
RESULT
NEG POS
ADD 1 TO
OVERFLOW = 1
LSB
INTERMEDIATE
SELECT ROUNDING MODE
RP
RESULT
.
INEX2 1
GUARD 0
ROUND 0
STICKY 0
NEG
ENTRY
EXIT
AND STICKY ARE
GUARD, ROUND,
AND STICKY BITS = 0
CHOPPED
RZ
GUARD, ROUND,
EXACT RESULT
EXIT
MOTOROLA