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USB Superspeed Peripherals

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I am trying to use the CYUSB3KIT-0003 FX3 to forwards GPIO to USB3 through GPIF.


I created two DMA channels :

  • One from USB3 channel 1 ( INPUT 0x01) to GPIF PIB BLOCK 0 .
  • One from GPIF PIB BLOCK 4 to USB3 channel 1 (OUTPUT 0x81).

Next I have the configuration for my GPIF state machine where I wait for a DMA request on thread0 and write the data on the corresponding DATA_BUS (8bits). After writing I jump to another state where I compare (with the action CMP_DATA) the value of one bit on the databus that I come to write.  Indeed, I want to read back my data bus value to the USB3 channel OUTPUT only when I receive from my USB3 channel INPUT a packet with the bit 5 at 1.


Can I compare the value of the databus using CMP_DATA with the value databus value I come to set ?


I don't know if the mistake come from my state model or my DMA configuration.


Below how are configured my DMA channels :


        dmaCfg.prodSckId = CY_U3P_UIB_SOCKET_PROD_1;
        dmaCfg.consSckId = (CyU3PDmaSocketId_t)CyU3PDmaGetSckId (CY_U3P_PIB_IP_BLOCK_ID, 0);
        apiRetStatus = CyU3PDmaChannelCreate (&glChHandleUSBIn,
                                              CY_U3P_DMA_TYPE_AUTO, &dmaCfg);


        dmaCfg.prodSckId = (CyU3PDmaSocketId_t)CyU3PDmaGetSckId (CY_U3P_PIB_IP_BLOCK_ID, 4);
        dmaCfg.consSckId = CY_U3P_UIB_SOCKET_CONS_1;
        apiRetStatus = CyU3PDmaChannelCreate (&glChHandleUSBOut,
                                              CY_U3P_DMA_TYPE_AUTO, &dmaCfg);


The state machine attached.




I hope I was clear enough.


Thank you by advance.

2 Replies
Not applicable



Yes, this is feasible. You can proceed with your design.




- Madhu Sudhan

Not applicable

Thank you Madhu Sudhan for your reply.


Unfortunatly I didn't find a way to do it... The write works but I never receive read data...


I tried to test a simple loop that read/write byte by byte on the databus. But I am still stuck...


I made a new state machine with only 3 states : DMA_WAIT WRITE READ.


On the DMA_WAIT state I have a simple transition, when a DMA_RDY_TH0 occurs I jump to WRITE.


On WRITE I have one action (DR_DATA). Because I juste want to write on byte, I unchecked "Update new value from data source" and "Repeat actions until next transition". The unique transition is a Logic_one that goes to READ.


On Read I have 2 actions : IN_DATA and COMMIT because I only want to read 8bytes and send the value on the USB3 socket. I also unchecked the ''Repeat actions until next transition". I set a DMA_RDY_TH0 transition to go back to WRITE and a ! DMA_RDY_TH0 to go to DMA_WAIT.


The first byte is well write on the data bus, but after I have nothing more (no read and write after) .... I can't read data, or write more...


Could you explain where I am wrong please ?