MC68LC040RC25A Datasheet, PDF (251/442 Pages) Freescale Semiconductor, Inc – M68040 Users Manual

Freescale Semiconductor, Inc.
they can be used to read the FPIAR in an exception handler without changing the
previous value. A reset or a restore operation of the null state clears the FPIAR.
9.3 FLOATING-POINT DATA FORMATS AND DATA TYPES
The M68000 floating-point model (MC68881, MC68882, MC68040) supports the following
data formats: single precision, double precision, extended precision, and packed decimal.
The M68000 floating-point model supports the following data types: normalized, zeros,
infinities, denormalized numbers, and NANs. The MC68040 supports part of the M68000
floating-point model in hardware. Table 9-2 lists the data formats and data types
supported by the MC68040. Tables 9-3 through 9-6 summarize the floating-point data
formats and data types details. For further information on the data formats and data types,
refer to the M68000UM/AD, M68000 Family Programmer’s Reference Manual.
Table 9-2. MC68040 FPU Data Formats and Data Types
Data Formats
Number
Types
Single-
Precision
Real
Double-
Precision
Real
Extended-
Precision
Real
Packed-
Decimal
Real
Normalized
*
*
*
†
Zero
*
*
*
†
Infinity
*
*
*
†
NAN
*
*
*
†
Denormalized
†
†
†
†
Unnormalized
†
†
*Data Format/Type Supported by On-Chip MC68040 FPU Hardware
†Data Format/Type Supported by Software (MC68040FPSP)
Byte
Integer
*
*
Word
Integer
*
*
Long -
Word
Integer
*
*
MOTOROLA
M68040 USER’S MANUAL
9-7
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