Ethernut 3.1 Rev-D

Documents

Hardware References

Ethernut 3.1 Rev-D Hardware User's Manual
including all schematics.

Ethernut 3 Memory Map
Ethernut 3 memory layout.

Ethernut 3 CPLD
A detailed description of the CPLD registers.

enut31d.zip
Eagle 4.11 schematic and board file.

Programming

Solving Incompatibilities
How to create firmware binaries running on Ethernut 3.1 and 3.0.

Nut/OS on Ethernut 3
How to install Nut/OS with a cross compiler and try a few sample applications on Ethernut 3.

JTAG Interface
Introduction to Ethernut 3 JTAG programming. Additionally describes how to restore the TFTP Boot Loader.

OpenOCD and Ethernut 3
How to use OpenOCD with Ethernut 3 and Turtelizer 2.

Booting Ethernut 3
explains in detail how to get your Ethernut 3 application running after power-up.

NPL Upgrade
How to upgrade the CPLD logic. It explains how to build and upload a new contents for the CPLD easily within seconds and without any special programming adapter.

Clock
An introduction to the programmable clock chip used on Ethernut 3.0 Rev-D and Rev-E.

Changes Compared to Version 3.0 Rev-E

Several parts had been replaced on board version 3.1:

IC2 DM9000(E) had been replaced by the new DM9000A. Advantages are:
- Smaller package
- Auto-MDIX support
The disadvantages are:
- Wakeup pin not available in 16-bit mode
- Wait pin not available in 16-bit mode
- Incompatible LED function (link indicator with 100Mbit only)
Auto-MDIX requires a different RJ-45 magnetics. We chose one with tab-up for better readability of the LEDs. However, this type is slightly larger and may not work with existing add-on boards.
IC7 X1286A8 (Intersil) is no longer recommended for new designs and had been replaced by the PCF8563T (NXP). The bad news is, that the replacement comes without EEPROM.
Logic gates IC11 and IC12 74LVC1G00GW had been replaced by a single 74AUP2G04GW as IC11. However, IC12 had been re-used as a chip select inverter for IC2 to maintain backward compatibility.
The 1A fuse had been replaced by a 0.5A type.
LED resistors had been reduced from 180Ω to 120Ω.

The following parts had been added:

An AT45DB321D-SU serial DataFlash had been added. The WAKEUP signal is no longer available and the related pin is used here as a chip select.
A common mode choke had been added to the power supply input to reduce EMI.
New 15pF capacitors C53..C56 had been added to the Ethernet lines to reduce EMI.
Pads had been added for a serial EEPROM, which may be used for Ethernet Controller boot configuration. However, no parted will be mounted by default.

The following parts had been removed:

Open drain driver IC13 is no longer required, because the new Ethernet Controller does not provides any NWAIT signal.
R28 had been removed, because the related output at IC10 is not connected.

Finally all known bugs of the predecessor 3.0 Rev-E had been fixed:

The MMC write protect switch is now routed to the correct pin.
Ceramic capacitor C5, 470nF, had been replaced by a 10uF tantalum to provide better supply stability while inserting an SD-Card.

Known Bugs

Due to a missing pull-up resistor, the FBUSY line of the NOR Flash is not functioning. Alternative methods like the toggle bit algorithm or data polling must be used.