(read, write or command) and waits for a response. The root
processor waits for a packet from the host. Once a packet is
received, it decodes the packet and identifies if it is a read,
write or a command packet. It performs the necessary action
and once completed, sends an acknowledge packet back to
the host. Once the host receives the acknowledgement, the
transaction is completed.
Comport Read—The command code shown in Table 1 allows
the root to recognize that the host wants to read some data
from a comport. The root processor identifies the read command and the address in the packet. It initiates a bus read to
the appropriate comport. Once the read is complete from the
bus, it sends the acknowledge packet with the received data
embedded in it. Once the host receives the acknowledge, the
received data is stripped out of the packet and the transaction
is complete. Figure 8 describes the read functionality.
Comport Write—The command code shown in Table 1 allows
the root to recognize that the host wants to write some data to