miniDSP Ltd, Hong Kong /
www.minidsp.com
/ Features and specifications subject to change without prior notice
7
2
C
ONNECTIVITY
2.1
USB
AND OPTICAL
(
BOX AND KIT VERSIONS
)
Connect as shown (for either box or kit version). The optical input and output will receive and transmit either stereo
SPDIF or 8-channel ADAT, depending on the loaded firmware.
2.2
I2S/TDM
CONNECTIVITY
(
KIT VERSION ONLY
)
I2S, or Inter-IC Sound, is a simple protocol used to carry digital audio information between digital chips (ICs) and
circuit boards. The USBStreamer circuit board provides 8 channels of I2S input and 8 channels of I2S output via a 12-
pin header. All channels can operate simultaneously at sample rates of up to 192 kHz. I2S pinouts are shown on the
next page.
Please note that I2S connectivity is intended for
advanced
DIY use only. You will need the knowledge to understand
digital clocking and wiring, and have access to the equipment necessary to be able to debug any issues you may run
into. (While miniDSP always tries to help its customers, it is infeasible for us to debug your circuit and wiring for
you.)
Be sure to take the following precautions when designing your I2S interface and wiring:
General I2S usage notes
•
Unbuffered I2S lines must be kept short to ensure clock and data integrity.
•
If driving longer lines, buffers may be required for the clock signals (MCLK, LRCLK, and BLCK).
•
Observe correct grounding and shielding, and keep analog and digital grounds separated.
•
Ensure that the clock ratios (as listed on the next page) are compatible with connected circuits.
Clock master
The USBStreamer always operates as clock master – that is, the clock lines are always outputs. The connected
circuitry must therefore use the clocks provided by the USBStreamer.
3.3V logic level
All lines use a 3.3V logic level. Ensure that connected circuits use a compatible level (1.8V, for example, will not
work).
