Analog Devices adsp-2100 Manual page 380

In the LO mode, the input is interpreted as the lower half of a double
precision number. In performing the EXP operation on a double precision
number, the higher half of the number must first be processed with EXP in
the HI or HIX mode, and then the lower half can be processed with EXP in
the LO mode. If the upper half contained a non-sign bit, then the correct
Shift Code was generated in the HI or HIX operation and that is the code
that is stored in SE. If, however, the upper half was all sign bits, then EXP
in the LO mode totals the number of leading sign bits in the double
precision word and stores the resulting Shift Code in SE.
Status Generated:
ASTAT: 7
SS MV AQ AS
*
SS Set by the MSB of the input for an EXP operation in the HI
or HIX mode with AV = 0. Set by the MSB inverted in the
HIX mode with AV = 1. Not affected by operations in the
LO mode.
Instruction Format:
Conditional Shift Operation, Instruction Type 16:
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 0 0 1
SF Shifter Function
1 1 0 0 EXP (HI)
1 1 0 1 EXP (HIX)
1 1 1 0 EXP (LO)
Xop: shifter operand
6 5 4 3
AC AV AN AZ
– – – –
1 1 0 0 SF
DERIVE EXPONENT
2 1 0
– – –
Xop 0 0 0 0
COND: condition
SHIFTER
15
COND
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