Datasheet

National Semiconductor Page 7 www.national.com
2.3 Automatic Device Detection & Configuration
The SPIO-4 system supports automatic hardware detection and configuration of the device under test.
The GUI software actually carries out the device detection and configuration task. The FPGA is re-
configured on the fly by the host PC when the SPIO-4 Board is powered on, or whenever ADC evaluation
boards are exchanged and SPIO-4 power is cycled.
Each DUT board has either an FPGA configuration file, or a microcontroller firmware module, unique to it.
The GUI software, in conjunction with the USB micro-controller, determines which DUT board has been
plugged in. It then loads a configuration file tailored for that DUT board into the FPGA and/or the
microcontroller.
Normally, the configuration process is totally transparent to the user, and requires no intervention.
However, some devices may allow this process to be overridden. Refer to the evaluation board manual
for more information.
Important Note: Many of our device evaluation boards do require jumper configurations to select
channels, voltages, or other options. Please consult the manual that came with the evaluation board for
specific information.
Important Note: Please be aware that DUT boards are NOT hot swappable. Please power
down both the SPIO-4 board and the DUT board prior to swapping DUT board.
2.4 LED Indicators
There are several LED indicators on the SPIO4 board. the ones described bleow are driven directly by
separate power rails on the SPIO4 board but as those rails can only be controlled by the processor they
not only indicate a particular rails is on, they also show a state of the SPIO4 firmware as discussed below.
Led D# Description
D10 Indicates power (USB or External) is present to SPIO board
D5 3.3V Digital IO Voltage for SPIO Board is up (required for all
operations)
D6 1.2V for FPGA core voltage – Indicates processor has completed
low level hardware initialization and is ready to program the FPGA
D11 1.8V for PSRAM core voltage - Indicates processor has completed
low level hardware initialization and is able to use the PSRAM
D7 & D8 3.3V & 5V DUT Supplies – Indicates the processor has detected a
DUT board inserted and has powered it
Table 3 - LED Behavior
2.5 DUT Interface (GPSI-16/32)
The SPIO-4 Data Capture Board is connected to the DUT through the GPSI-16/32 (J6) connector. As
described previously, the GPSI-32 interface provides control, data and power to the DUT board. See
Table 1 below for signal specifics. The GPSI-16/32 interface also supports a subset within it called GPSI-
16 which consists of the lower order pins 1-16. A given DUT board may use a 16-pin, GPSI-16 port only,
or may use the whole 32-pin port. GPSI-16 has level shifters allowing some of the DUT interface
voltages to go from 1.65V to 5.5V LVTTL levels under the direct control of the DUT board circuitry. To
achieve that voltage range the voltage level shifters are NOT bidirectional. A DUT board requiring bi-
directional signals must use the upper-order portion of the GPSI-32. Note, however, that upper order
portion of GPSI-32 requires adherence to 3.3V LVTTL voltage levels as it does not have level shifters.