8.2 In a carry-lookahead adder, there are two additional signals defined, , (generate), (propagate). Derive the Boolean equation for the carry-out bit Co using only G, Pi(where i=0, 1) and C0.

7. Suppose we want to sum 100,000 numbers on a single-bus multiprocessorcomputer. Let's assume we have 10 processors. The first step would be to split the set ofnumbers into subsets of the same size. All processors start the program by running thefollowing loop that sums their subset of numbers, where Pn is its processor index (0~9):sum/Pn] = 0；for (I = 10000 * Pn；I ＜10000*(Pn+1)；I=I+1) sum(Pn] = sum[Pn] + Al]； / sum the assigned areasThe next step is to add these many partial sums, so we divide to conquer. Half ofprocessors add pairs of partial sums, then a quarter add pairs of the new partial sums,and so on until we have the single, final sum. We want each processor to have its ownversion of loop counter variable I, so we must indicate that it is a "private" variable.In this problem, the two processors must synchronize before the "consumer" processortries to read the result from the memory location written by the "producer" processor,otherwise, the consumer may read the old value of the data. Here is the code (halfis alsoa private variable):Question: according to the algorithm, find out what operations are executed by thedesignated processor during the designated repeat-loop iteration. (Ex: NOP or sum[0] =sum[0] + sum [4]). Copy Table 7 to your answer sheet and fill in the answers.

題組內容

8.2 In a carry-lookahead adder, there are two additional signals defined, , (generate), (propagate). Derive the Boolean equation for the carry-out bit Co using only G, Pi(where i=0, 1) and C₀.

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