The IBM z900 decimal arithmetic unit

As the cost for adding functions to a processor continues to decline, processor designs are including many additional features. An example of this trend is the appearance of graphics engines and compression engines on midrange and even low end microprocessors. One area that has the potential to capture chip real estate is the decimal arithmetic engine because of its importance in financial and business applications. Studies show that 55% of the numeric data stored on commercial databases are in decimal format. Although decimal arithmetic is supported in many software languages it is not yet available on many microprocessors. This paper details the decimal arithmetic engine in the recently announced z900 microprocessor.