Introduction

DSM520 is a OEM product made by REDSonic. It is based on Sigma's EM8620 SoC and REDSonic's DMA platform.

You can see some pictures of it here. You can discuss about this device in the forum.

Hardware

General info

CPU: Sigma EM8620L 166MHz ARM Media SoC
Memory: 64MB 166MHz DDR333 (2 x NT5DS16M16CS-6K 16Mx16)
Flash: xx (8MB ?)
USB Controller: NEC µPD720101GJ USB2.0 Host controller
Ethernet: 100Mb/s (Realtek RTL8100BL)
WiFI: Atheros

Connectors

 JP1 (TTL console for EM8620L):
  1 - TX
  2 - GND
  3 - +3v ?
  4 - GND
  5 - RX

 JP2 (TTL console for LPC921F):
  1 - +?v
  2 - TX
  3 - RX
  4 - RST (CPU Reset)
  5 - GND

 JP5 (JTAG ?):
  1 - +5v
  2 - x - 3.3
  3 - x - 0
  4 -     0
  5 -     0
  6 - GND
  7 - 
  8 - GND
  9 -      2
 10 - GND

 JP7 (Power):
  1 - +12v (Yellow)
  2 - GND
  3 - GND
  4 - +5v (Red)

Firmware

REDSonic DMA platform (SecureSOHO based)
Running uClinux 2.4.22-uc0-sigma-20050328-nm
Firmware is scrambled by inverting the firmware image.
Internal name: DMA DSM520-1-00-Golden-b

Tips and tricks

Enable telnet

Connect a TTL serial converter to JP1.
Press ~ on serial console. This loads telnet daemon.
Type this via telnet to enable telnet permanently:

 # cfg -conf_change MASS_PRODUCT 1
 # cfg -save

Change from NTSC to PAL mode

Type this via telnet:

 # cfg -conf_change CONFIG_DMA_ENABLE_PAL 1
 # cfg -conf_change NTSC_OR_PAL PAL
 # cfg -save

Console commands

 s = setup menu
 m = media menu
 h = shuffle (play mode)
 l = setup menu
 1-9 = presets
 y = video out select
 § = down
 " = audio out select
 ¤ = up
 / = firmware upgrade
 ~ = enable telnet daemon
 > = DEV_SetTVMode 122 (PAL)
 < = Factory default
 ? = dev mode ? - hangs box
 Y = Display properties (saturation/brightness/contrast)
 A = Volume Up
 S = Volume Down
 N = Online Zone
 M = Volume Mute
 - = strange config mode - hangs box

DSM-520 hacking blog

29.12.05 - JTAG project

I have taken the motherboard out of the DSM now and are going to solder on a 10 pin connector on JP5 to see if we got any JTAG signals there. I don't think I have enough solder wick to take of the wave soldering from the IDE port, but if I have I will try to solder on a connector on there as well.

Projects