• Table of contents
• Motorola C123
  • Specifications
  • Hardware
    • Schematics
    • GSM Chipset
    • NOR Flash
    • SRAM
    • Display
    • Test Points
      • Test points surrounding Iota
      • Test points surrounding Calypso
      • Test points accessible from battery compartment
    • Charger Connector
    • Antenna Connector
    • PCB photographs

Motorola C123¶

The C123 seems to be one of many ODM phones that Motorola bought from Compal communications in Taiwan. It seems (nearly?) identical with the C118.

The internal name of the hardware is E88

Specifications¶

• GSM 900 / GSM 1800 dual-band
• 101x45x21 mm, 86 grams
• no GPRS
• 920mAh Li-Ion battery
• Ti Calypso/Iota/Rita chipset

Hardware¶

Schematics¶

The schematics (part of the Level 3 Service Manual) can be found at various mobile phone related
websites, including http://www.uydudoktoru.com/dosyalar/gsmschema/20061016154029.rar

GSM Chipset¶

• DBB: Ti Calypso Baseband, D751749ZHH model (Calypso Lite G2), includes 256kBytes of internal SRAM
• ABB: Ti TWL3025BZGR
• RF: TRF6151C
• RF PA: SKY77324-12

NOR Flash¶

• Intel 28F160C3TD (16Mbits, i.e. 2 MByte) Advanced+ Boot Block Flash Memory (C3)
• Data sheet will be in git

SRAM¶

• ESMT M24L2161128SA-70BE (128k x16, i.e. 256kByte)
• Data sheet available from vendor

Display¶

The display is a 96x64 pixels monochrome LCD, attached via I2C bus to the Calypso DBB chip.

The LCD controller inside the display is a Sitronix ST7558,
for which the data sheet is available. There is a community-based driver part of osmocom-bb

Test Points¶

Test points surrounding Iota¶

• TP4 -- BS_TDO, the JTAG TDO signal of the Iota (connected to TDI of Calypso)
• TP5 -- Iota:TESTV pin
• TP7 -- Uita:CK13M, connected from Calypso:CLK13M_OUT
• TP29 -- Iota:ADIN1 (VADCID)
• TP111 -- Iota:UDR (USP Rx), connects to Calypso:MCUDO
• TP110 -- Iota:UEN (USP Enable), connects to Calypso:MCUEN0
• TP112 -- Iota:ONNOFF
• TP114 -- Intoa:ITWAKEUP, connects to Calypso:RTC_ALARM
• TP113 -- Iota:RESPWONZ, connects to Calypso:RTSPWRONZ
• TP116 -- Iota:TEST3
• TP117 -- Iota:TEST4

Test points surrounding Calypso¶

• TP11 -- Calypso:DSR_MODEM
• TP12 -- Calypso:RTS_MODEM
• TP23 -- Calypso:nCS4
• TP46 -- Calypso:CLK32K_OUT, connects to Iota:CK32K
• TP118 -- Calypso:EXT_IRQ, connects to Iota:INT2
• TP115 -- Calypso:EXT_FIQ, connects to Iota:INT1
• TP45 -- Calypso:SCLK (I2C)
• TP30 -- Calypso:nSCS1 (I2C)
• TP44 -- Calypso:SDO (I2C)
• TP34 -- Calyspo:nCS2
• TP48 -- Calypso:nCS3/INT4N
• TP49 -- Calypso:VRDBB_1.5V
• J2 -- Calypso NM_DAI_INTERFACE (MCSI_TXD, MCSI_CLK, MCSI_RXD, MCSI_RSYNCH, GND)

Test points accessible from battery compartment¶

!MotorolaC123:compal_testpads.png!

On the C123 the following pads are usable

• TP27 -- DLPWR (download power on), connects to Iota:RPWON
• TP14 -- RxD Modem
• TP13 -- TxD Modem
• TP9 -- CTS Modem
• TP39 -- GND

On most phones other pads are grounded and not usable (like in the scan above).
Known exceptions

• C115 and C117 have all test pads
• C155 has JTAG but not IRDA UART test pads

Charger Connector¶

The charger connector is a barrel-type with 3mm diameter and a segmented shaft. The top ring is not connected, the lower ring is GND. The top pin supplies +5V to the phone.

Antenna Connector¶

The antenna connector is a MS-147.

PCB photographs¶

Available from Pictures of each individual PCB layer can be found here: [http://www.steve-m.de/pictures/compal_e88/] or at MotorolaC123PCB