AH
B
Ma
st
e
r
In
te
rf
a
ce
AH
B
Sl
a
ve
I
n
te
rf
a
ce
To Bus
Matrix
To Bus
Matrix
DMA
Controller
MEDIA ACCESS
CONTROLLER (MAC)
MAC Control /
Status Registers
IEEE 1588
Power
Management
Module (PMM)
MAC Management
Counters (MMC)
Offload Engine
DMA
Control /
Status
Registers
RX Module
TX Module
Serial
Management
Interface (SMI)
2002 / 2008 / PPS
CRC
CRC
Filtering / VLAN / SA / CRC
Physical Layer
Interface (PHY)
EN0MDC
EN0MDIO
TX Pair
RX Pair
TX/RX
Controller
TX FIFO
RX FIFO
MI
I /
R
MI
I
In
te
rf
a
ce
To External PHY
From External PHY
EMACPC.PHYEXT
EMACPC.PHYEXT
RX
TX
RX
TX
0
1
EMACPC.
PHYEXT
Block Diagram
884
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Ethernet Controller
15.2 Block Diagram
shows the block diagram of the Ethernet MAC with an integrated PHY interface.
Figure 15-1. Ethernet MAC With Integrated PHY Interface
15.3 Functional Description
The Ethernet Controller comprises the following submodules:
•
Clock Control
•
Media-Independent Interface (MII) / Reduced Media-Independent Interface (RMII) Module
•
DMA Controller
•
Transmit/Receive Controller (TX/RX Controller)
•
Media Access Controller (MAC)
•
AHB Bus Interface
•
PHY Interface
The following sections describe the features and functions of each submodule.
15.3.1 Ethernet Clock Control
Available clock sources are dependent on the interface chosen. The following sections describe the clock
control for the various interfaces.
15.3.1.1 PHY Interface
The Ethernet Controller module and Integrated PHY receive two clock inputs, as follows:
•
A gated system clock acts as the clock source to the Control and Status registers (CSR) of the
Ethernet MAC. The SYSCLK frequency for run, sleep, and deep sleep modes is programmed into the
System Control module. See
for more information on programming SYSCLK and enabling
the Ethernet MAC.
•
The PHY receives the main oscillator (MOSC) which must be 25 MHz ±50 ppm for proper operation.
The MOSC source can be a single-ended source or a crystal.
shows the clock inputs to
the Ethernet Controller module.