Digital Subscriber Line Access Multiplexer (DSLAM) Example Design

Digital Subscriber Line Access Multiplexer (DSLAM) Example Design
// transform the IP header based on the routing information
//
// Size:
// 221 instructions
//
// Example usage:
// ATM_IP_Route_Lookup_And_Transform(status, net_model, $ip_header, \
// llc_encap_type, fifo_addr, cnx_entry_address, sdram_buff_addr)
3.1.4 Egress Microblock
Two egress microblocks are available for the receive microblock group in the Receive Processor:
• DSLAM_Enqueue (enqueues packets to the transmit microblock group)
• DSLAM_SA_Enqueue (enqueues exception packets to the StrongARM core)
The following macro headers describe the egress microblocks for outgoing PDUs and flow control
packets. They are contained in the file $Gen_DSLAM\hyannis\
microblocks\dslam_rx_ublock_group_a.uc.
// DSLAM_Enqueue
//
// Description:
// This is an egress block that queues either a flow control
// packet or a PDU to a ring buffer for ingress into the
// transmit microblock group.
//
// Inputs:
// packet_type type of packet (control or data) (if
// supporting control packets)
// pdu_completion whether the PDU is complete, if packet type
// is data
// buffer_descriptor_address address for buffer descriptor
// physical_port_type ATM, Ethernet, Frame Relay, etc.
// connection_entry_address index of connection entry
// pdu_length length of PDU in buffer
//
// Implementation:
// if packet_type is control
// enqueue the flow control packet
// else
// enqueue the PDU
//
// Size:
// 61 instructions (without flow control packet support and without other
// protocol support)
// with other protocol support, +18 instructions
// with flow control packet support, +25 instructions
//
// Example usage:
// DSLAM_Enqueue(pkt_type, pdu_complete, bd_address, phy_port_type, \
// cnx_entry_address, length)
//
// DSLAM_SA_Enqueue
//
// Description:
// This is an egress block that queues an ATM PDU to the
// StrongARM core for exception processing.
//
// Inputs:
Application Note 17