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Motorola DSP96002 User Manual

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MOTOROLA

DSP96002 USER’S MANUAL

D-15

lowing the above operation, the Data ALU register will be read first by a single precision and then by a dou-

ble precision floating-point move.

- 32-bit data from source is $00200000 (= +2**(-128))
- exp = $00 (8 bit bias)
- mantissa = $200000 (the hidden bit is zero)

- data stored in the register
- e = 380 (incorrect representation with 11-bit bias; the
correct representation would be 37F)
- I = 0 (the number is unnormalized)
- U-TAG = 1 (set; the number cannot be used in computations
without adding extra cycles for normalization,
since it is unnormalized)
- fraction = 40000000
- mantissa = 0.010...00

In this last case, the U-TAG tells us that an operation using this operand will first add extra cycles to nor-

malize it. However, an SP move will render the correct result since the "formatting" scheme presented in

Section 5.5 chooses the right bits. One should notice that a double precision floating-point move that reads