Digilent HW with 32 digital IO channels

[JAlaj]

Hello Team,

Please suggest if there is any available hardware wherein i can have 32 MISO lines, 1Chip select, 1 CLK and 1 MOSI

Thanks,

Jalaj

[JColvin]

Hi @JAlaj,

The Digital Discovery has enough pins to support this, though with so many separate devices that are being driven by the clock and controller out peripheral in (MOSI) lines, I would image that the drive strength of the signal would start to become a concern as well. However, it is my understanding that the Multi MISO option is only available in the Spy sub-tab for the SPI function within the Protocol instrument.

Ostensibly, it may be possible to do some sort of custom setup where you have the Logic Analyzer continuously capturing data on the 32 MISO lines and then a separate Pattern Generator instrument running a custom pattern controlling the remaining three SPI control signals to tell all the peripheral devices to periodically take a sample (or whatever function the peripheral devices are doing), but I have not attempted such a large scale setup.

Thanks,
JColvin

[JAlaj]

6 minutes ago, JColvin said:

Hi @JAlaj,

The Digital Discovery has enough pins to support this, though with so many separate devices that are being driven by the clock and controller out peripheral in (MOSI) lines, I would image that the drive strength of the signal would start to become a concern as well. However, it is my understanding that the Multi MISO option is only available in the Spy sub-tab for the SPI function within the Protocol instrument.

Ostensibly, it may be possible to do some sort of custom setup where you have the Logic Analyzer continuously capturing data on the 32 MISO lines and then a separate Pattern Generator instrument running a custom pattern controlling the remaining three SPI control signals to tell all the peripheral devices to periodically take a sample (or whatever function the peripheral devices are doing), but I have not attempted such a large scale setup.

Thanks,
JColvin

Thanks JColvin

I have not attempted this capture yet. I am trying to understand the overall setup using Digilent Discovery. If drive strength becomes bottleneck, then i will have to design Buffer ckt on board. But i was first curious to understand the HW requirements, and settings in GUI. Regarding your suggestion of different SPI pattern generator and Logic Analyzer, do you mean i should use two Digital Discoveries HW?

[attila]

Hi @JAlaj

Select 40bit sampling and add 32, 33 SPI interpreters