SMSC LAN9420 - Manual (Page 23)

Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface
Datasheet
SMSC LAN9420/LAN9420i 23 Revision 1.22 (09-25-08)
DATASHEET
Chapter 3 Functional Description
3.1 Functional Overview
The LAN9420/LAN9420i Ethernet Controller consists of five major functional blocks. These blocks are:
„ PCI Bridge (PCIB)
„ System Control Block (SCB)
„ DMA Controller (DMAC)
„ 10/100 Ethernet MAC
„ 10/100 Ethernet PHY
The following sections discuss the features of each block. A block diagram of LAN9420/LAN9420i is
shown in
Figure 1.2 LAN9420/LAN9420i Internal Block Diagram on page 11 .
3.2 PCI Bridge (PCIB)
The PCI Bridge (PCIB) facilitates LAN9420/LAN9420i’s operation on a PCI bus as a device. It has the
following features:
PCI Master Interface: This interface connects LAN9420/LAN9420i to the PCI bus when it is
functioning as a PCI Master. It is used by the DMA engines to directly access the PCI Host’s memory.
PCI Target Interface: This interface connects LAN9420/LAN9420i to the PCI bus when it is functioning
as a PCI Target. It provides access to PCI Configuration Space Control and Status Register (CONFIG
CSR), and access to the Control and Status Registers (CSR) via I/O or Non-Prefetchable (NP) memory
accesses. In addition, Big/Little Endian support for the registers may be selected.
PCI Power Management Support: LAN9420/LAN9420i supports PCI Bus Power Management
Interface Specification Rev. 1.1. Refer to
Section 3.7, "Power Management," on page 73 for more
information.
Interrupt Gating Logic: This logic controls assertion of the nINT signal to the Host system.
PCI Configuration Space Control and Status Registers (CONFIG CSR): The Host system controls
and monitors the LAN9420/LAN9420i device using registers in this space.