priority just lower than timing information the medium bandwidth and high compression require a small fifo buffer 521 memory write information 530 comes from peripherals and memory system 202 the information flow occurs primarily in bursts of high activity interspersed with times of low activity this memory write information 530 is typically transmitted with low compression a high bandwidth is required to accommodate the bursts trace packet merge unit 237 gives this data an intermediate priority just lower than program counter flow information 520 the irregular rate and low compression require a large fifo two level buffer 531 memory read information 540 also comes from peripherals and memory system 202 memory read information 540 is similar to memory write information 530 memory read information 540 occurs primarily in bursts of high activity interspersed with times of low activity and is generally transmitted with low compression a high bandwidth is required to accommodate the bursts trace packet merge unit 237 gives this data an intermediate priority just lower than memory write information 530 the irregular rate and low compression require a large fifo two level buffer 541 application supplied data 550 comes from central processing unit mailbox 203 it is difficult to characterize this data because it varies depending on the application program running on central processing unit 201 application supplied data 550 is generally believed to occur in bursts with a low average bandwidth this data is typically transmitted with low compression application supplied data 550 has a low priority in trace packet merge unit 237 below that of the memory write information 530 and memory read information 540 the particular application program determines the size required of fifo buffer 551 asic supplied data 560 comes from asic data source.