Motorola DSP96002 User Manual
Page 760
D-8
DSP96002 USER’S MANUAL
MOTOROLA
register file consisting of 10 96-bit registers for storage of floating-point numbers is available for
that purpose. An automatic conversion unit converts the floating point storage format in memory
to the internal DP format when moving operands and/or results from/to memory.
2.
Multiply unit: A full IEEE floating-point multiply unit, delivering either a SP or SEP result in one
instruction cycle.
3.
Adder/Subtracter unit: A full IEEE floating-point adder/subtracter unit, which can deliver the
sum as well as the difference of two operands in the same instruction cycle, to either SP or SEP.
4.
Special function unit: A special function unit provides various logic functions, as well as support
for divide and square root in terms of an initial seed for a fast convergent divide and square root
algorithm.
5.
Controller and arbitrator: A controller/arbitrator supplies all of the control signals necessary for
the operation of the data ALU.
The data ALU uses the SEP format for all of its operations: the results are automatically rounded to either
SP or SEP. All of the rounding modes specified by the IEEE standard are supported. These rounding modes
are:
Figure D-5. DP Format in the Data ALU
95 94 93 92
75 74
64
63 62
32
31
11 10
0
S U V
O
E
0
Fraction (MSBs)
Fraction (LSBs)
i
Dn.h
Dn.m
Dn.l
S : sign
U : single precision unnormalized tag
V : double precision unnormalized
i : explicit integer
Tiny SP Numbers between
±
2
Emin
-1.0
Ч
2
-126
0
+1.0
Ч
2
-126
Figure D-6. Tiny Numbers
Figure D-7. SEP Format in the Data ALU
95 94 93 92
75 74
64
63 62
32 31
11 10
0
S U V
O
E
0
Fraction
0
i
Dn.h
Dn.m
Dn.l