Changes

This block performs the initial reading of the packet. It skips through the packet header and reads the first two bytes of the payload, which contain the target location and packet type. (The latter is not to be confused with the packet type specified in the packet header. Our packets have a separate branding convention.) Based on these, the module will reject the packet (request a "skip" of the packet in the receive FIFO buffer) if the packet's contents will not be necessary further. The Reader will return control to the [[FPGA_Idler|Idler (010)]] if the packet is not addressed to its location or the packet type is invalid. Otherwise it will yield control to the module relevant to the packet type.

This block performs the initial reading of the packet. It skips through the packet header and reads the first two bytes of the payload, which contain the target location and packet type. (The latter is not to be confused with the packet type specified in the packet header. Our packets have a separate branding convention.) Based on these, the module will reject the packet (request a "skip" of the packet in the receive FIFO buffer) if the packet's contents will not be necessary further. The Reader will return control to the [[FPGA_Idler|Idler (010)]] if the packet is not addressed to its location or the packet type is invalid. Otherwise it will yield control to the module relevant to the packet type.

[[Image:ReaderProcess.png|frame]]

[[Image:ReaderProcess.png|frame|width:236px]]

Block 011 is the only block with switching between following states.  Its first task is to load the MAC data of the packet.  If filtering inside of the FPGA is required, this block is responsible for it.  The only MAC filtering likely to be needed is a check to see if the destination MAC address matches the MAC address of the CP2200/1, but the CP2200/1 should filter this itself (verify in the data sheet).  If the packet is bad, this block tells the CP2200/1 to skip the packet and returns to block 010.  The MAC filter would be the first substate.

Block 011 is the only block with switching between following states.  Its first task is to load the MAC data of the packet.  If filtering inside of the FPGA is required, this block is responsible for it.  The only MAC filtering likely to be needed is a check to see if the destination MAC address matches the MAC address of the CP2200/1, but the CP2200/1 should filter this itself (verify in the data sheet).  If the packet is bad, this block tells the CP2200/1 to skip the packet and returns to block 010.  The MAC filter would be the first substate.