Motorola MVME197LE manual Floating Point Support, CPU/MPU Registers

Floating Point Support

CPU/MPU Registers

MPU register CR20 is reserved for usage by the debugger. If CR20 is to be used by the user program, it must be restored prior to utilizing debugger resources (system calls).

Floating Point Support	4
The floating point Special Function Unit (SFU) of the MC88110 microprocessor
chip is supported in this version of 197Bug. For MVME197Bug, 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:

		Integer Data Types
	12		Byte
	1234		Half-Word
	123455678		Word
	Floating Point Data Types
1_FF_7FFFFF			Single Precision Real Format
1_7FF_FFFFFFFFFFFFF			Double Precision Real Format
-3.12345678901234501_E+123			Scientific Notation Format (decimal)

When entering data in single or double precision 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.

MVME197LEIG/D1 4-7