3Com 3CRWDR100A-72

The device is based on Texas Instrument AR7, so you need the target.ar7 in OpenWrt trunk.

OpenWrt status

Untested, probably unsupportable due to limited RAM.

Hardware Highlights

CPU Ram Flash Network USB Serial JTag
AR7 TNETD7300AGDW ??MB 2MiB 4 x 1 No Yes Yes

Basic hardware info

The device has the following connectors on the rear (left to right).

  • Auxiliary antenna.
  • ADSL input connector.
  • Power connector (12V 1.2A).
  • Reset button.
  • Large On/Off button.
  • 4 numbered RJ45 10/100 MBit connectors.
  • Main antenna.

Hardware

Main processor

The main processor is a Texas Instruments TNETD7300AGDW Processor, an AR7 that should work with the target.ar7 of OpenWrt (yet untested).

Memory

Onboard is a PSC A2V28S40BTP SDRAM Memory chip.

Flash

The flash chip is an Intel TE28F160C3-B 16Mbit (2MiB) 3.0V Flash memory.

Switch chip

The internal switch is a Marvell 88E6060-RCJ 6-port (4 external, 1 to the router itself, 1 unused) 10/100 switch with autosensing.

Wireless card

The wireless chip in mini-pci card is a Texas Instruments TNETW1130GVF, also known as ACX111 chipset.

Photos

3crwdr100a-72_front.jpg

Serial

A serial console can be connected to J4.

The serial signals are at a 3.3V level, so you need to use a level convertor, see serial.console

The serial signal itself is 115200 baud, 8 databits, 1 stopbit, no parity (8N1).

The pinout for the serial is

pin signal
1 Not Connected
2 Not Connected
3 RX
4 Not Connected
5 TX
6 Not Connected
7 Not Connected
8 Not Connected
9 GND
10 VCC +3.3V

Disposition on the board:

9 7 5 3 1
10 8 6 4 2

TODO add output log

JTAG

3crwdr100a-72_jtag.jpg

To enable JTAG functionality, you must short-circuit SHORT pins or put 100R resistor. (At your own risk)

I couldn't write (nor read properly) my flash because I suspect it was broken. But not sure.

But AR7 prom's was read properly.

The AR7 chip has a small memory banks on the chip : 4Kb PROM (@0xBFC00000) and 4Kb RAM (@0x80000000)

The FLASH is located at 0x90000000 (CS0) and RAM is located at 0x94000000 (CS1)

These address extracted from http://www.linux-mips.org/wiki/AR7#Memory+map:http://www.linux-mips.org/wiki/AR7#Memory map

See port.jtag and JTAG tools for more JTAG details.

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toh/3com/3crwdr100a-72.txt · Last modified: 2012/03/29 23:16 by orca