
ELECTRONICS
S5N8947 (ADSL/Cable Modem MCU)
SAMSUNG ELECTRONICS
Page : 25
MagIC Team
6.4. Ethernet Controller
The S5N8947 has an Ethernet controller which operates at either 100/10-Mbits per second in half-
duplex or full-duplex mode. In half-duplex mode, the controller supports the IEEE 802.3 Carrier Sense
Multiple Access with Collision Detection (CSMA/CD) protocol. In full-duplex mode, it supports the IEEE
802.3 MAC Control Layer, including the Pause operation for flow control.
6.4.1. Block Diagram
S
Y
S
T
E
M
B
U
S
B
D
I
M
I
I
/
10
M
b
p
s
7
-
W
i
r
e
BDMA Tx
Buffer
Controller
BDMA Tx
Buffer
(64 words)
Bus Arbiter/
Controller
BDMA Rx
Buffer
(64 words)
BDMA Rx
Buffer
Controller
CAM
Contents
Memory
(32-words)
BDMA
control and
status
register
MAX Tx
Buffer
(80 bytes)
MAX Tx
Buffer
Controller
MAC
MAX Rx
Buffer
(16 bytes)
MAX Rx
Buffer
controller
Address
CAM
Interface
and
comparator
Flow
Controller
CRC
Checker
MAC control
and status
register
Station
Manager
BDMA+SBUS I/F
32
32
32
32
32
32
8
8
Figure 7 Ethernet controller block diagram
6.4.2.
Features and Benefits
The most important features and benefits of the S5N8947 Ethernet controller are follows :
l
Cost-effective connection to an external Repeater Interface Controller(RIC)/Ethernet backbone
l
Buffered DMA (BDMA) engine using Burst mode
l
BDMA Tx/Rx buffers (256 bytes/256 bytes)
l
MAC Tx/Rx FIFOs (80 bytes/16 bytes) to support re-transmit after collision without DMA request
and to handle DMA latency
l
Data alignment logic
l
Supports for old and new media (compatible with existing 10-Mbit/s networks)
l
Full IEEE 802.3 compatibility for existing applications
l
Provides a standard Media Independent Interface (MII)
l
Provides an external 7-wire interface, also.