Motorola MVME197LE manual Single Precision Real, Double Precision Real, Scientific Notation

Using the 197Bug Debugger

Single Precision Real

4

This format would appear in memory as:

1-bit sign field	(1 binary digit)
8-bit biased exponent field	(2 hex digits. Bias = $7F)
23-bit fraction field	(6 hex digits)

A single precision number takes 4 bytes in memory.

Double Precision Real

This format would appear in memory as:

1-bit sign field	(1 binary digit)
11-bit biased exponent field	(3 hex digits. Bias = $3FF)
52-bit fraction field	(13 hex digits)

A double precision number takes 8 bytes in memory.

Note

The single and double precision formats have an implied integer bit (always 1).

Scientific Notation

This format provides a convenient way to enter and display a floating point decimal number. Internally, the number is assembled into a packed decimal number and then converted into a number of the specified data type.

Entering data in this format requires the following fields:

An optional sign bit (+ or -).

One decimal digit followed by a decimal point.

Up to 17 decimal digits (at least one must be entered).

An optional Exponent field that consists of:

An optional underscore.

The Exponent field identifier, letter “E”.

An optional Exponent sign (+, -).

From 1 to 3 decimal digits.

For more information about the floating point SFU, refer to the MVME197BUG 197Bug Debugging Package User’s Manual.

4-8 Installation Guide