Sony Ericsson J100i

The J100i seems to be one of many ODM phones that Sony Ericsson bought from Compal communications in Taiwan.

j100i.jpg j100i_back.jpg


  • GSM 900 / GSM 1800 dual-band (J100i)
  • GSM 850 / GSM 1900 dual-band (J100a)
  • 100 x 44 x 18 mm, 79g
  • STN 65k - 96 x 64 pixels
  • 900mAh Li-Po battery
  • Ti Calypso/Iota/Rita chipset



large version: [raw-se_j110_pcb.jpg]


They can be found here:

GSM Chipset

  • DBB: Ti Calypso Baseband, D751749ZHH model (Calypso Lite G2), includes 256kBytes of internal SRAM
  • ABB: Ti TWL3025BZ
  • RF: Ti TRF 6151CJ
  • RF PA: SKY77328-13

NOR Flash + SRAM

  • Intel RD38F1010C0ZTL0
    • 32MBit NOR (4 MByte)
    • 4Mbit SRAM (512 KByte)

Audio ringtone

  • Macronix MX92U832AZCG (unknown datasheet)


The display is a 96 x 64 pixels CSTN color display attached to the Calypso DBB via the uWire interface (nReset, nSCS0, SCK, SDO). The backlight is controlled by the DBB IO1.
Exact model unknown for now.

Test points

There are some easily accessible test points (i.e. bigsqare and not very small round pads behind the rf shields).

Theses test points are divided in two groups (when looking from behind the phone) :

  • A group of 7 TPs at the lower left of the PCB. Accessible from the battery compartment without disassembly except for the first one. From left to right :
    • TP16: JTAG TDO
    • TP9: CTS MODEM
    • TP13: TX MODEM
    • TP14: RX MODEM
    • TP3: DL PWR
    • TP107: GND
    • TP19: VBAT
  • A group of 5 TPs at the middle/upper right of the PCB. Theses are not accessible without disassembly, but could be by cutting a small plastic strip just right of the hole made for the battery connector. From left to right:
    • TP18: JTAG TMS
    • TP20: BAT_TEMP
    • TP17: JTAG TCK
    • TP15: VCHG
    • TP8: JTAG TDI

Misc notes

Serial cable

You can use a standard Sony Ericsson USB cable, since the USB pins match the RX/TX pins of the Calypso UART. You just need to build some USB-A female to serial converter:

picture source: Simon Eugster, CC-BY-SA


pin number USB pin UART pin color
1 +5V nc red
2 D- RxD (Device to PC) white
3 D+ TxD (PC to Device) green
4 - ground black

See the J100i cable how-to which has been sent in by 'timrrr': [raw-J100i_cable.pdf]


  • The RAM loader of the J100i is the same as used on the MotorolaC140 series and it works fine with osmocon. It however expects a "1003" magic word to be present at address 0x803ce0.
  • To bypass this limitation, use the Calypso romloader to chainload the application. Here's an example for loading layer1bin:
$ cd osmocom-bb/src/
$ host/osmocon/osmocon -p /dev/ttyUSB0 -m c140 -c target/firmware/board/se_j100/layer1.highram.bin
  • If this doesn't work, try c140xor

Stock firmware notes

Below are some notes related to the stock SE's firmware.

MMI codes

The following MMI codes were found in the firmware dump near the address 0x00196cc0:

  • #82# - HW/SW information,
  • #89#, #890# - HW tests (keyboard, LCD, speaker),
  • #0000#, #0008# - reset UI language to English.

Updated by fixeria 5 months ago · 21 revisions

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