Digital Discovery : 32Ch LA or 24 Ch?

[hwg]

I’m looking at the Digital Discovery: Portable Logic Analyzer

http://store.digilentinc.com/digital-discovery-portable-logic-analyzer-and-digital-pattern-generator/

In the description on that page, it says, “32-channel digital logic analyzer (1.2…3.3V CMOS, 8 channels at 800MS/s*, 16 channels at 400MS/s*, and 32 channels at 200MS/s)”

So it looks like it’s a 32-Ch logic analyzer.

But in the reference documentation   https://reference.digilentinc.com/reference/instrumentation/digital-discovery/start

it says:

Digital Logic Analyzer
Channels	24

And the connectors are:

·         A 32-pin connector with 24 digital inputs

·         Right side 12-pin connector with 8 digital I/O’s

·         Left side 12-pin connector with 8 digital I/O’s

It’s not clear whether the Left and/or Right side digital I/O’s can be viewed along with the other 24 Digital inputs from the large connector, to provide 32-Ch logic analysis.

For my application, I need to view the state of up to 32 Ch simultaneously, so I’d like to know if this unit has 32-Ch logic analyzer capability.

[attila]

Hi @hwg

The Digital Discovery has 24 high speed capable inputs (DIN) and 16 input/output lines (DIO).
The Logic Analyzer in WaveForms application lets you acquire at the same time up to 32 lines: DIN0:23 and DIN24:31 or DIN0:15 and DIO24:47
The DIN and DIO lines have different termination (internal circuitry) and this could lead to different signal delays. The level of this depends on the analyzed circuit/driver used wires/cabling, but normally it should be less than 10ns, 100MHz.

https://reference.digilentinc.com/reference/instrumentation/digital-discovery/reference-manual#io_level_translators
https://reference.digilentinc.com/reference/instrumentation/digital-discovery/reference-manual#input_dividers