grant the request or notify the sender of the request that the system has no resources available for establishing the requested packet connection in various embodiments once a packet connection has been granted a physical connection will be established between the data source and data destination for this physical connection will be torn down once the packet transfer has been complete and the data source has sent out an end_of_packet signal on its forward flow control port at that point all resources used by this connection will be release back to the pool of allocated and free resource the following illustrates a command format in an embodiment commands are sent by functional modules on the transmit_data_port and the transmit_upward_status_port in multi word format in the order shown each command word on the transmit_data_port is accompanied by a cmd_valid status on the transmit_upward_status_port 0 u2014 data source or peripheral functional module drives data transaction 1 u2014 switch module drives data transaction switch module generates read enable and read address 0 u2014 write address is generated by destination functional or peripheral module 1 u2014 write address is generated by switch module 22 16 remote module id for a push command it is the data destination id for a pull command it is the data source id 15 8 addressing descriptor pointer at source used when the switch module generates read address at data source 7 0 addressing descriptor pointer at destination used when the switch module generates write address at the destination when the remote unit is a peripheral module 1 st word 22 1 and the command is a pull 1 st.