Communication Interface Functional Overview
Ethernet Controllers
Copyright © 2002 Marvell
CONFIDENTIAL
Doc. No. MV-S300165-00, Rev. A
May 21, 2002, Preliminary
Document Classification: Proprietary Information
Page 61
Section 7. Communication Interface Functional
Overview
The GT-64260A integrates the following into its communication unit:
•
Three Ethernet controllers
•
Two MPSC controllers
•
An I
2
C interface
•
SDMAs
•
Baud Rate Generators (BRG)
7.1
Ethernet Controllers
There are three 10/100 Mbps full duplex Ethernet ports in the GT-64260A. Each port is fully compliant with the
IEEE 802.3 and 802.3u standards and integrates MAC function and a dual speed MII interface. The Ethernet ports
can be configured to MII or RMII (three Ethernet ports configuration is available only with RMII). The port’s speed
(10 or 100Mb/s) as well as the duplex mode (half or full duplex) is Auto-Negotiated through the PHY and does not
require user intervention.
The Ethernet interface implements the following pins: E0[14:0], E1[14:0], MDC, and MDIO. The E0 and E1 pins
are multiplexed to support MII and RMII configurations.
Notes
•
For Ethernet pin multiplexing information, MII, and RMII mode pin descriptions, see the GT-64260A
datasheet.
Since the serial ports have different configurations and part of them "wake-up" after reset as tri-state pins, the fol-
lowing pull downs are required. However, it is recommended to pull down all unused pins for electrical protection
from software errors.
•
If not using port E0 and to minimize the number of pull downs, configure the port to MII and pull down pins
E0[1] and E0[14:6].
•
When E0 is configured as two RMII ports, pins E0[7] and E0[14] are not connected and must be pulled down.
If only one of the two RMIIs are used (Ethernet controller 0), pins E0[13] and E0[11:10] must not be connected
and must be pulled down.
•
If not using port E1 and to minimize the number of pull downs, configure the port to MII and pull down pins
E1[1] and E1[14:6].
–
When E1 is configured as an RMII port, pins E1[1], E1[7:6], E1[12:10], and E1[14] are not connected and
must be pulled down.