Hello All, I have concerns about a PID routine which is doing some calculations with 32-bit values. It uses multiply and add instructions. My concern about this is, how to detect overflow. A overflow can result in a process correction with a wrong sign and this is not acceptable for the process. What I need in a overflow situation is a saturated value. In the past I was using a 8052, multiplying 32-bit values was possible but it was done in a lot of 8-bit portions. With the ARM I can do the same in one instruction but I am missing the overflow flag. Is there a option to detect an overflow after a multiply? I am using the LPC2129 (ARM7) Greetings Aalt -- ============================== Aalt Lokhorst Schut Geometrische Meettechniek bv Duinkerkenstraat 21 9723 BN Groningen P.O. Box 5225 9700 GE Groningen The Netherlands Tel: +31-50-5877877 Fax: +31-50-5877899 E-mail: Lokhorst@... ==============================
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How to detect a multiply overflow?
2005-08-09 by Aalt Lokhorst