Reference Manual

Turbo PMAC/PMAC2 Software Reference

Turbo PMAC On-line Command Specification 355

Example:

M150->DP:$052000

M250->DP$052001

See Also:

M-Variables (Computational Features)

Dual-Ported RAM (Writing a Host Communications Program)

On-line commands M{constant}, M{constant}->,

.......... M{constant}->F:{address}, M{constant}={expression}

Program command M{constant}={expression}

M{constant}->F:{address}

Function: Dual-Ported RAM Floating-Point M-Variable Definition

Scope: Global

Syntax: M{constant}[..{constant}]->F[:]{address}

where:

 {constant} is an integer from 0 to 8191 representing the number of the M-variable;

 the optional second{constant} must be at least as great as the first {constant} -- it represents

the number of the end of the range;

 {address} is an integer constant from $000000 to $FFFFFF (0 to 16,777,215 if specified in

decimal).

This command causes Turbo PMAC to define the specified M-variable or range of M-variables to point to

32 bits of data in the low 16 bits of both X and Y memory at the specified location in Turbo PMAC’s

address space. The data is interpreted as a floating-point value with the IEEE single-precision (32-bit)

format.

The definition consists of the letter F, an optional colon (:), and the word address.

This format is mainly useful only for dual-ported RAM locations $050000 to $05FFFF (Option 2

required). With this format, the host can read or write to the corresponding location with the standard

IEEE 32-bit floating-point data format.

The IEEE 32-bit floating point format has the sign bit in bit 31 (MSB); the biased exponent in bits 30 to

23 (the exponent is this value minus 127), and the fraction in bits 22 to 0 (there is an implied 1 added to

the fraction in the mantissa). The words are arranged in the standard Intel format.

Example:

M155->F:$054001

M255->F$05402