LAN9117 Datasheet, PDF (6/114 Pages) SMSC Corporation – HIGH PERFORMANCE SINGLE-CHIP 10/100 NON-PCI ETHERNET CONTROLLER

LAN9117
1.1 Internal Block Overview
This section provides an overview of each of these functional blocks as shown in Figure 1-2, "Internal Block Diagram".
FIGURE 1-2:
INTERNAL BLOCK DIAGRAM
+3.3V
25MHz
+3.3V
EEPROM
(Optional)
PME
Wakup Indicator
Power
Management
16-bit SRAM I/F
Host Bus Interface
(HBI)
PIO Controller
IRQ
FIFO_SEL
Interrupt
Controller
GP Timer
3.3V to 1.8V
Core Regulator
2kB to 14kB
Configurable TX FIFO
TX Status FIFO
RX Status FIFO
2kB to 14kB
Configurable RX FIFO
PLL
3.3V to 1.8V
PLL Regulator
10/100
Ethernet
MAC
MIL - RX Elastic
Buffer - 128 bytes
MIL - TX Elastic
Buffer - 2K bytes
EEPROM
Controller
10/100
Ethernet LAN
PHY
Optional
External PHY - MII
Interface
1.2 10/100 Ethernet PHY
The LAN9117 integrates an IEEE 802.3 physical layer for twisted pair Ethernet applications. The PHY can be configured
for either 100 Mbps (100Base-TX) or 10 Mbps (10Base-T) Ethernet operation in either full or half duplex configurations.
The PHY block includes auto-negotiation.
Minimal external components are required for the utilization of the Integrated PHY.
1.3 10/100 Ethernet MAC
The transmit and receive data paths are separate within the MAC allowing the highest performance especially in full
duplex mode. The data paths connect to the PIO interface Function via separate busses to increase performance. Pay-
load data as well as transmit and receive status is passed on these busses.
A third internal bus is used to access the MAC’s Control and Status Registers (CSR’s). This bus is accessible from the
host through the PIO interface function.
On the backend, the MAC interfaces with the internal 10/100 PHY through a the MII (Media Independent Interface) port
internal to the LAN9117. The MAC CSR's also provides a mechanism for accessing the PHY’s internal registers through
the internal SMI (Serial Management Interface) bus.
The Ethernet MAC can also communicate with an external PHY. This mode however, is optional.
The MAC Interface Layer (MIL), within the MAC, contains a 2K Byte transmit and a 128 Byte receive FIFO which is sep-
arate from the TX and RX FIFOs. The FIFOs within the MAC are not directly accessible from the host interface. The
differentiation between the TX/RX FIFO memory buffers and the MAC buffers is that when the transmit or receive pack-
ets are in the MAC buffers, the host no longer can control or access the TX or RX data. The MAC buffers (both TX and
RX) are in effect the working buffers of the Ethernet MAC logic. In the case of reception, the data must be moved first
to the RX FIFOs for the host to access the data. For TX operations, the MIL operates in store-and-forward mode and
will queue an entire frame before beginning transmission.
DS00002267A-page 6
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