AP1617

The AP1617 is designed as one kind of pre- and post-scale 32-bit-values for the MDU (shifting/rotating of double-words). By using the MDU it is very often necessary to scale the value before or after the calculation to avoid truncation errors during the calculation. Scaling is most easily realized by multipling with a factor of 2X which is a simple left shift, e.g. VALUE * 23 >> shift VALUE three(3) positions to the left.

The following routines will show you a very effective way for shifting a 32-bit value with the 16-bit ALU using the General Purpose Registers (GPR) more than one bit position. The first routine shows a shift left; the principle used here can also be applied to perform right shifts as well as rotate left or right operations. The last routine shows the rotating of a double-word by 0 to 31 bit positions to the right. If you want to know more information such as the electrical characteristics about the AP1617, please download the datasheet in www.seekic.com or www.chinaicmart.com .