Answer4

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	WHAT'S YOUR ENGINEERING QUOTIENT?
•Take a Swing! Problem 4—An application needs to implement a signed 16 ı 16 bit integral multiplication. If the processor can implement only one 8 ı 8 bit multiplication instruction, is a signed multiply instruction more convenient? Answer: A signed 8 ı 8 multiplication can only be applied to the product of the most significant bytes of the two 16-bit operands. All other cross products cannot directly use the signed multiplication. It is more convenient to convert both 16-bit operands to unsigned, remember the sign of the product, then use unsigned 8 ı 8 multiplication for all four cross products. 1-00 For questions or comments about Test Your EQ, e-mail eq@circuitcellar.com.