8.2
Digital Control
www.ti.com
EVM Operation
Figure 6. Amplifier Selection Switches
The digital control signals can be applied directly to J5 (top or bottom side). The modular ADS1278EVM
can also be connected directly to a DSP or microcontroller interface board, such as the 5-6KINTERFACE
or HPA-MCUINTERFACE boards available from Texas Instruments, or the MMB0 if purchased as part of
the ADS1278EVM-PDK. For a list of compatible interface and/or accessory boards for the EVM or the
ADS1278, see the relevant product folder on the TI web site. Some of the digital signals are controlled
directly with pins on J5. Other signals such as the Power Down controls can only be controlled with slide
switches or by U17 and U18 that are set up and read using the I
2
C signals on pins 16 and 18 of J5. The
Format and Mode pins can be controlled by all three methods (slide switches, GPIO pins on J5, and the
I
2
C control from U17).
The ADS1278 allows the serial interface to be used in two different formats: an SPI-compatible mode and
a frame-sync format. Switch S12 can be used to switch between these two formats. The left position,
marked
SPI
, selects the SPI format. In this format, the signals are connected in this configuration:
SBAU129C – November 2007 – Revised July 2008
ADS1178EVM, ADS1278EVM, ADS1178EVM-PDK, and ADS1278EVM-PDK
11