Motorola MVME166, Installation Manual

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Floating Point Support
MVME166IG/D2 4-17
4
Floating Point Support
The floating point unit (FPU) of the MC68040 microprocessor chip is
supported in 166Bug. For MVME166Bug, the commands MD, MM, RM, and
RS
have been extended to allow display and modification of floating point
data in registers and in memory. Floating point instructions can be
assembled/disassembled with the DI option of the MD and MM commands.
Valid data types that can be used when modifying a floating point data
register or a floating point memory location:
When entering data in single, double, extended precision, or packed decimal
format, the following rules must be observed:
1. The sign field is the first field and is a binary field.
2. The exponent field is the second field and is a hexadecimal field.
3. The mantissa field is the last field and is a hexadecimal field.
4. The sign field, the exponent field, and at least the first digit of the mantissa
field must be present (any unspecified digits in the mantissa field are set
to zero).
5. Each field must be separated from adjacent fields by an underscore.
6. All the digit positions in the sign and exponent fields must be present.
Integer Data Types
12 Byte
1234 Word
12345678 Longword
Floating Point Data Types
1_FF_7FFFFF Single Precision Real Format
1_7FF_FFFFFFFFFFFFF Double Precision Real Format
1_7FFF_FFFFFFFFFFFFFFFF Extended Precision Real Format
1111_2103_123456789ABCDEF01 Packed Decimal Real Format
-3.123456789012123 Scientific Notation Format (decimal)