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TLP Packet Format: FIG: TLP Packet Format. The Transaction Layer Packet Format is defined as: Starts with a Prefix, which is an optional one and, TLP Header and then, With/Without Data Payload, At the end of TLP Packet a TLP Digest, The information in TLP Packet Format is distributed as: TLP Prefixes. Header (mandatory). Data (included when applicable): depends on the transaction type. TLP Digest (optional). FIG: TLP Byte Information TLP Header: Provides Format of the packet. Type of the packet. Length of associated data, if available. Transaction Descriptor. Address/Routing information Byte enables Message encoding Completion Status FIG: Common TLP Header. 32-bit if information. Provides: Format, TLP Packet Type, Traffic Class info, Attributes, T Heads (Presence of TLP Prefix, if present), TLP Digest, End Point (TLP is Normal or Poisoned), Address Translation (When memory is available). Length (Data Length notation denoted in 32bit words) F

System Verilog: Multiplexer

Fig: Multiplexer Multiplexer in digital circuit design is a circuit which selects one of its input by using the SELECT line. select[1:0] q 00 d[0] 01 d[1] 10 d[2] 11 d[3] FIG: 4 X 1 MUX. (Not Completely labeled); q1, q2, q3, q4 are the 4 outputs; a stands for and gate; o stands for or gate; n stands for not gate. SV Code (Gate-level model): module mux_gate_level( select, d, q ); input logic [1:0] select; input logic [3:0] d; output logic q; wire q1, q2, q3, q4; wire [1:0] SelectBar; not n1( SelectBar[0], select[0] ); not n2( SelectBar[1], select[1] ); and a1( q1, SelectBar[0], SelectBar[1], d[0] ); and a2( q2, select[0] , SelectBar[1], d[1] ); and a3( q3, SelectBar[0], select[1] , d[2] ); and a4( q4, select[0] , select[1] , d[3] ); or o1( q, q1, q2, q3, q4 ); endmodule SV Code (using assign statement): //mux using assign statement

PCI Configuration Space Registers (Type 0 / Type 1)

PCI Configuration Space Type 0 is for PCI devices and, for Endpoints in case of PCIe. Type 1 Config Space is for PCI host controller and, for PCI Root Complex in case of PCIe. Type 0/1 Configuration Space: FIG: Config Space. The Config Space registers are common for both type 0/1. Device ID and Vendor ID: Identify the particular device. Status register: Provides error information, updated information, etc. Command register: Controls Bus Master and different utilities. Class code: Provides category of the device (Host Controller, IDE Bridge, SATA Controller, Ethernet Controller, etc). Revision ID of PCI. BIST - Built-In Self Test. Header Type Specific area is defined by Header type (0 or 1). Cache Line Size. Table: Configuration Space Registers. Table: Command Register Table: Status Register FIG: Type 0 Configuration Space Table: TYPE 0 Registers FIG: PCIe TYPE 1 Configuration Space Table: TYPE 1 Configuration Space Registers

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