Write a program loop whose instructions can be broadcast from the control processor in Figure 12.1 that will enable an array processor to iteratively compute temperatures in a plane, as discussed in Section 12.2. In addition to instructions that shift the network register contents between adjacent processing elements (PES), assume that there are two-operand instructions for moves between PE registers and local memory and for arithmetic operations. Assume also that each PE stores the current estimate of its grid point temperature in a local memory location named CURRENT and that a few registers, RO, R1, and so on, are available for processing. Each boundary PE maintains a fixed boundary temperature value in its network register and does not execute the broadcast program. A small value stored in location EPSILON in each PE is used to determine when the local temperature has reached the required level of accuracy. At the end of each iteration of the loop, each PE must set its status bit, STATUS, to 1 if its new temperature satisfies the following condition:

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[New temperature - [CURRENT]] < [EPSILON] Otherwise, STATUS is set to 0.