NB2DSK-SPK01 Resources - Board ID Memory
Board identification is handled courtesy of a DS2406 device (from Dallas Semiconductor). Although the device is actually a dual-addressable switch, it is used for the additional 1kbit of memory that it possesses.
The DS2406 is a 1-Wire® compatible device, primarily used to contain a code with which to identify the speaker board when plugged in. The NanoTalk Controller interrogates this device over a single wire, the associated signal of which is AUD_1WIRE
.
The DS2406 supports half-duplex communication at a rate of up to 16.3kbits/s. Although power for the device is sourced over the same single wire as the data itself – courtesy of a parasitic capacitor which charges when the 1-Wire bus signal line is High – the device is also fed from the NB2DSK-SPK01's 3.3V supply, to ensure continuous power.
Similar devices on the NB2DSK01 motherboard, all peripheral boards and 3-connector daughter boards, allow the NanoTalk Controller to detect which specific boards are available to the system.
Location on Board
The DS2406 device (designated U1
) is located on the component side of the board, to the top-left of the 16-way connector (HDR1
).
Schematic Reference
The 1-Wire memory device can be found on sheet 1WB_DS2406_EPROM.SchDoc
(entitled 1-Wire Bus ID) of the speaker board schematics.
Further Device Information
For more information on the DS2406 device, refer to the associated datasheet (DS2406.pdf
) available at www.maxim-ic.com.