SocLib Components General Index

VciVgmn Functional Description

This hardware component is a generic micro-network respecting the VCI advanced protocol. It behaves as two fully independent packet switched network for VCU commands and VCI responses, and supports several simultaneous transaction. When several initiators try to reach the same target, the arbitration policy is round-robin. It gives the system designer a generic "communication black-box" with a parametrized number of VCI initiator ports (NB_INITIATOR), and a parameterized number of VCI target ports (NB_TARGET). This component can be used to build a "flat" interconnect, where all VCI initiators and targets are identified by a single index:

• The VCI targets must be indexed from 0 to (NB_TARGET - 1).
• The VCI initiators must be indexed from 0 to (NB_INITIATOR - 1).

As any VCI advanced compliant interconnect, this component uses the MSB bits of the VCI ADDRESS field to route the command packets to the proper target, thanks to a routing table, implemented as a ROM. This routing table is build by the constructor from the informations stored in the mapping table. It uses the VCI RSRCID field to route the response packet to the initiator.

This component has two "structural" parameters, that can be used to fit the behaviour of a specific physical micro-network:

• The MinLatency parameter is a number of cycles that defines the latency of an empty network.
• The FifoDepth parameter can be increased to improve the saturation threshold.

VciVgmn CABA Implementation

The caba implementation is in

• source:trunk/soclib/systemc/include/caba/interconnect/vci_vgmn.h
• source:trunk/soclib/systemc/src/caba/interconnect/vci_vgmn.cc

Template parameters

template<
     typename vci_param,   //  VCI parameters
     size_t NB_INITIAT,   // number of VCI initiators
     size_t NB_TARGET,   // number of VCI targets
     size_t MIN_LATENCY,   // minimal latency
     size_t FIFO_DEPTH>   // network storage capacity

Constructor parameters

VciVgmn(
     sc_module_name name,   //  Component Name
     const soclib::common::MappingTable &mt);   // MappingTable

Ports

• sc_in<bool> p_resetn : Global system reset
• sc_in<bool> p_clk : Global system clock
• soclib::caba::VciTarget<vci_param> p_from_initiator : Ports from VCI initiators
• soclib::caba::VciInitiator<vci_param> p_to_target : Ports to VCI targets