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< Flameman
Revision as of 13:06, 23 September 2019 by Legacy (talk | contribs) (Project: do something useful with the board)
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For more interesting projects done by Flameman, be sure to check out his project index



This project is deprecated, RIP. Jtag software is also deprecated, vendor removed the support for amcc44x.


  • add the JTAG connector at J10 (you could skip it, it is suggested)
  • build the JTAG cable
  • replace the bootloader u-Boot

People you could contact

  • Please let me know of any success or issues you encounter. carlojpisani@gmail.com
  • Guys at DTB, have new 2017-2019 projects


The board consists of:

  • CPU PowerPC 405GP running at 266mhz
  • RAM PC133 SDRAM slot, currently, only supports single sidded DIMMs
  • LAN On-chip 405GP ethernet, board doesn't have an ethernet MAC address (the monitor/bootloader is able to fix it)
  • UART DCE serial port, speeds up to 230k, only tested to 115200bps
  • PCI two pci slots, keyed for 5V only cards
  • IDE Promise Technologies PDC20265 IDE
  • ROM 512k of boot flash, AMD 29LV040B (amd29lv040b.pdf), soldered on the PCB, if you like to use a socket you have to consider the bootloader will check for the flash manufactor ID, so or you replace the 29LV040B with an other socked-29LV040B, or you have to modify the bootloader
  • POWER the board need to be 12v dc powered 2A max, it is able to feed the hard disk
  • System PCB 6.00" x 7.5" board size
  • RTC the real time clock chip is missing
  • RAM 32M PC133 SDRAM DIMM, the board has issues with more than 128M: if you inspect the pcb, you will see that the DIMM connector has same pin missing, this is the reason why you can't use DIMM bigger than 128M
  • PCI additional ethernet board needed cause the on board ethernet is implemented by the IBM-ppc-405GP, for example netbsd is not able to drive it, so in case you need an additional board, the one provided with DHT is good enough

Images of the board


see more detailed photo dht-walnut-ppc405-top


The BEST solution is to equip your lab with the bdi2000. This hardware is expensive a lot, 'cause it is not a simple download cable, it's a professional debugger

For this dht-walnut project it has been used "OCD Commander is macraigor's free debugger software", that i'm going to illustrate



  • Netbsd has a port for "IBM PowerPC 405GP based Walnut evaluation board", this is not the DHT-Walnut, this is another way to call the AMCC-Walnut (yes just to be confusing). Ok, it is not for DHT-Walnut, but this port could be (easily / hardly) adapted to the DHT-Walnut with some work



See Flameman/dht-walnut/develop

if you need pci-riser

PCI Riser Card 5V 32-bit 2 Slot passive Edge connector X1 of the riser card is inserted in a free 5 V 32-bit slot on the PC motherboard. Slot X2 is then connected and ready for use. The second PCI slot X3 receives its special signals for bus arbitration and interrupt control via the cable from card X4, which is inserted in any other slot on the PCI motherboards. The assembly does not contain any active components. This means that the board is suitable for operation with V(I/O) = 5 V as well as V(I/O) = 3.3 V. The coding of connectors X2 and X3 with this variant is for V(I/O) = 5 V.