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3.2
Data Output
Digital Interface
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All logic levels on J5 are 3.3V CMOS, except for the I
2
C™ pins. These pins conform to 3.3V I
2
C rules.
describes the J5 serial interface pins.
Table 3. J5: Serial Interface Pins
Pin No.
Pin Name
Signal Name
I/O Type
Pullup
Function
J5.1
CNTL
SYNC
In
High
—
J5.2
GPIO0
MODE0
In
High
—
J5.3
CLKX
SCLK
In
None
ADS1278 SPI clock
J5.4
DGND
DGND
In/Out
None
Digital ground
J5.5
CLKR
CLKR
Out
None
SCLK clock
J5.6
GPIO1
MODE1
In
High
—
J5.7
FSX
DRDY/FSYNC
In/Out
Low
—
J5.8
GPIO2
FORMAT0
In
High
—
J5.9
FSR
DRDY/FSYNC
In/Out
None
—
J5.10
DGND
DGND
In/Out
None
Digital ground
J5.11
DX
DIN
In
None
ADS1278 SPI data
in
J5.12
GPIO3
FORMAT1
In
High
—
J5.13
DR
DOUT1
Out
None
ADS1278 data out
J5.14
GPIO4
FORMAT2
In
None
—
J5.15
/INT
DRDY/FSYNC
Out
None
—
J5.16
SCL
SCL
I
2
C
N/A
I
2
C clock
J5.17
TOUT
CLK
In
None
Can be used to
provide a clock from
a processor
J5.18
DGND
DGND
In/Out
None
Digital ground
J5.19
GPIO5
CLK Select
—
None
—
J5.20
SDA
SDA
I
2
C
N/A
I
2
C data
Many pins on J5 have weak pull-up/down resistors. These resistors provide default settings for many of
the control pins. Many pins on J5 correspond directly to ADS1278 pins. See the
for complete details on these pins.
Most data communications are directed through DOUT1. The data from all eight channels can be
observed on the DOUT1 pin using the TDM mode. That is the signal that is used by the
ADS1278EVM-PDK to read back and display all the channels. All the data output signals (DOUT1 to
DOUT8) can be monitored on J2.
illustrates the pinout for J2.
6
ADS1178EVM, ADS1278EVM, ADS1178EVM-PDK, and ADS1278EVM-PDK
SBAU129C – November 2007 – Revised July 2008