FX3 interfacing ADC at 100MHz

[Anonymous]

Dear all,

I never worked with the FX3 and I'm right now designing a data acquisition system which shall output 32bit of data at 100MHz but some of the logic behind the GPIF II port is still foggy for me.

Key aspects:

• The acquisition system has its own clock and can provide it to the PCLK pin as an input into the FX3
• It also provides the 32 bit parallel data to be sent to the host PC (I just need it to be sent as it is to the host pc)
• The device generating the data is an ADC and no buffering capability is available outside the FX3
• I cannot lose ADC samples

I'm looking into the "Stream IN" mode which seams to be the most appropriate for this application (correct me if I'm wrong). This is described in page 45 of "Designing with the EZ-USB® FX3™ Slave FIFO Interface"

My question:

I would like to have the ADC clock running freely, and when requested by software have the FX3 to start capturing samples at the rising edge of PCLK continuously for, let's say, 1000 ms . Do I still have to manage the PKTEND# ; SLOE# ; SLRD#; SLCS#; SLWR#; A[1:0] signals by hardware or is it possible to do everything in software ??

In other words, I would like that my interface with the FX3 is just PCLK and 32 Bit Data. Is that possible?

Thanks in advance,

Mario

[SrinathS_16 · Accepted solution]

Hello Mario Sousa,

Yes, your requirement can be done.

Please refer to the AN75779 app note (http://www.cypress.com/documentation/application-notes/an75779-how-implement-image-sensor-interface-... ) which interfaces to an image sensor. This does not make use of the SLWR, SLOE, SLCS, PKTEND, A[1:0] pins. Instead, the thread switching is taken care in the state machine and the IN_DATA action reads the data into the GPIF socket.

Best regards,

Srinath S