Occurrence of this PCB

The BT102 PCB is used in the following device models:

• BudgeTone 101 (1 network port, 10 Mbit)
• BudgeTone 102 (2 network ports due to builtin switch)

This manufacturer also produces other models.

These devices are end-of-life at GrandStream; their replacements use BT200 boards which are RoHS compliant and have more memory.

Components found

• DSP system-on-chip: TMS320VC5402, with an extensive user manual. The PGE100 version is green, in that it is RoHS-compliant and uses no Pb/Br.
• A second (important?) chip mysteriously hidden under paint. The most likely candidate is the same one as found in the GXP-2020 model: A coprocessor 320AIC20K from Texas Instruments interfaces speaker, microphone and line in/out to the DSP over I2C or S2C. It includes support for oversampling and filtering.
• Flash memory: 512k x 16, or 1024k x 8: MX29LV800BBTC-70. The cycle speed is 70 ns, making this flash suitable for running code directly. This means that smaller RAM will do.
• Static RAM: 128k x 16, or 256k x 8: IS61LV12816-107.
• Ethernet: RTL8019AS and on the models with a second ethernet connector also (TODO). The RTL8019AS is an NE2000 clone, albeit a bad one according to the Linux kernel. It does not really matter; at least example code is available in that kernel, and actually uIP has already been ported to these chips before.
• Switch: TODO

Connectors found

These are described centrally in more detail:

• JP1 is a mixed JTAG/bootloader connector
• JP2 connects to I/O peripherals: speaker, LCD, keyboard, LEDs. The peripherals are the same as used for BT200 boards.

The JTAG/bootloader connector used in these Grandstream phones is a 16-pin connector. Its solder islands are open on the PCB, so soldering in a 0.1" pitched two-row pin header is easy.