On-Chip Communication Architectures

318 CHAPTER 8 Custom Bus-Based On-Chip CA Design

the appropriate destination. The largest part of the crossbar is its data path, which

MUXes all input data channels to the output data channels. It is controlled by a split

channel for each input which specifi es which output to send the burst to. A merge

control channel is also required at the output to indicate which input to receive the

burst from. The split control comes from the input control block, while the merge

control comes from the output control block, as shown in the fi gure. In between

the input/output control and the data path are repeat circuits that replicate the

same split/merge ...