Tracing of test information from a hardware device for debugging is
formatted for transmission via a high-speed serial protocol. Data from
various components in the hardware device is transmitted to an external
test board using high speed serial ports. The number of serial ports
needed for data transfer is significantly less than a complimentary
parallel port configuration. Additional functional blocks on the chip
process the data for high speed serial output. The functional blocks
format information into subchannels, arbitrate data, append protocol,
perform data integrity checks, and serialize the data. The additional
blocks built on the chip to support the serial ports consume less chip
space than the space consumed by the number of parallel ports required to
provide equivalent data transfer rates. The process operates in near real
time and may use time stamping to correlate and reconstruct data from
different information sources. An input port receives data from the
external test component to modify registers or memory, set break points,
modify hardware status, communicate with processors, or modify other
operating conditions to debug the hardware device.