Abstract: A packet header processing engine includes a level 2 (L2) header generation unit and a level 3 (L3) header generation unit. The L2 and L3 header generation units are implemented in parallel with one another. The L2 generation unit may include a single execution section and the L3 generation unit may include multiple parallel execution sections. When both the L2 and L3 generation units complete their operations on a particular packet, a build component combines the generated L2 and L3 information to form a complete packet header.

Abstract: A packet header processing engine receives a header of a packet. The received header includes a size of the packet. A maximum transfer unit size of a destination interface of the packet may be determined. The packet header processing engine determines whether the size of the packet exceeds the maximum transfer unit size of the destination interface. If the size of the packet does not exceed the maximum transfer unit size of the destination interface, the packet header processing engine generates a new header from the received header. If the size of the packet exceeds the maximum transfer unit size of the destination interface, the packet header processing engine generates a fragment header from the received header. The packet header processing engine may recycle the fragment header for further processing in addition to forming a first fragment packet from the fragment header.

Abstract: A packet header processing engine includes a memory having a number of distinct portions for respectively storing different types of descriptor information for a header of a packet. A packet header processing unit includes a number of pointers corresponding to the number of distinct memory portions. The packet header processing unit is configured to retrieve the different types of descriptor information from the number of distinct memory portions and to generate header information from the different types of descriptor information.

Abstract: A packet header processing engine includes a level 2 (L2) header generation unit and a level 3 (L3) header generation unit. The L2 and L3 header generation units are implemented in parallel with one another. The L2 generation unit writes L2 header information to a first buffer and the L3 generation unit writes L3 header information to a second buffer. When the L2 and L3 header generation units finish processing a packet, the packet may be unloaded from the first and second buffer while a new packet is simultaneously loaded to the packet header processing engine.

Abstract: A packet header processing engine includes a level 2 (L2) header generation unit and a level 3 (L3) header generation unit. The L2 and L3 header generation units are implemented in parallel with one another. The L2 generation unit writes L2 header information to a first buffer and the L3 generation unit writes L3 header information to a second buffer. When both the L2 and L3 generation units complete their operations for a particular packet, a build component combines the generated L2 and L3 header information from the buffers to form a complete packet header.

Abstract: A packet header processing engine includes a level 2 (L2) header generation unit and a level 3 (L3) header generation unit. The L2 and L3 header generation units are implemented in parallel with one another. Mailbox registers allow the L2 and L3 header generation units to communicate with one another. The L2 header generation unit may write to a specified mailbox register only when a valid bit corresponding to the mailbox register indicates that the register does not contain valid data. After writing to the mailbox register, the L2 header generation unit changes the state of the valid bit. The L3 register then reads from the mailbox register and changes the state of the valid bit. A similar implementation of the mailbox registers allows data to flow from the L3 header generation unit to the L2 header generation unit.

Abstract: A system for determining a memory read latency includes a memory, a memory read circuit, and a latency detector. An identifiable pattern of data is written to at least one location in the memory, and a read request and the address of the identified pattern are sent to the memory. The latency detector determines a read latency period based on detecting the identifiable pattern of data.

Abstract: A node controller (12) includes a processor interface unit (24) that receives an interrupt signal (50). The processor interface unit (24) includes a register (52) with a forward enable bit (54). In response to the forward enable bit (54) being set, the processor interface unit (24) generates a forward interrupt signal (56) for transfer to an input/output interface unit (26) of the node controller (12). The input/output interface unit (26) generates an interrupt request for transfer to a remote node controller. The input/output interface unit (26) includes an interrupt destination register (58) that includes an identity of a particular remote node controller and associated processor interface unit to which the interrupt request is to be transferred. The remote node controller having a processor attached thereto to handle the interrupt request.