Can I calulate with IEEE floating point values on a PCD system?

FAQ #101188

Yes, a new set of instructions for calculation with IEEE floating point values (single and double) has been added to the firmware of PCD2.M480, PCD2.M5xx0 and PCD3.


Motorola FFP (Fast Floating Point) has been used for floating point calculations since the beginning of PCD history. In order to simplify the interface against systems which do not support FFp but IEEE format for floating point values the instruction set of the PCD has been extended. All "twin" of all instructions available for the calculation with FFP values are now also available for IEEE calculations.

What are the instructions in detail?
Each of the existing instructions for FFP (the default) do also exist for IEEE Float and IEEE Double data. 

  • For IEEE Float, precede the mnemonic with an 'E' character, for example EIFP, EFADD (instead of IFP or FADD) etc.
  • For IEEE Double, precede the mnemonic with 'D', for example: DIFP, DFSUB.

Minimum Firmware (FW) requirement for this feature

 System pilot FW version
 first production version

PCD systems not listed in this table do not support this function.


  • These instructions can only be used with PG5 2.0.
  • There is also a new instruction for the conversion from IEEE single to IEEE double (and vice versa):
    EFPD (single to double) and DFPE (double to single). These instructions are supported by firmware version 1.10.15 and later.
  • The instructions for convertig a IEEE double value to an integer value and vice versa (DFPI and DIFP) are working correctly starting with firmware 1.14.23.
  • IEEE single values can be displayed by the S-Web Server using the format "e" (e.g.,e


PCD2 / _Firmware Classic

PCD3 / _Firmware Classic

PG5 2.0 / SEdit (IL programming)

Last update: 31.05.2015 17:10

First release: 14.04.2009 17:26

Views: 49315

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