FX2LP18 Virtual Com Port

[JeBo_4132831]

Hi,

My question could sound strange but i'm wondering if it is possible to add Virtual Com Port functionnality onto our existing FX2LP18 Firmware / Host Software based onto CyUSB3.inf (that used GPIF and Slave FIFO ).

I could use the I2C channel to "emulate" UART.

Regards.

[Pranava_YN · Accepted solution]

Hi,

FX2LP should be configured as a composite device in order to enumerate it as both USB device and a COM port. 

Please refer to KBA which specifies how to configure FX2LP descriptors to operate it as 2 COM ports. - https://community.cypress.com/t5/Knowledge-Base-Articles/FX2LP-Dual-Virtual-COM-Port-Descriptors-KBA...
How are you planning to use I2C interface to implement UART?

[JeBo_4132831]

OK, i ll have a look to this KBA. Yes i plan to use I2C to implement a "false" UART.

Our goal is to be able to send message from our FPGA/FX2LP to the PC HOST. The com port seems a good choice.

I can share you my dsc.asm perhaps to help me add this virtual com port ....

I'm currently using EP2/EP6 in my firmware. So for virtual com port i should use EP1 and EP8 ?

[JeBo_4132831]

Is it possible that someone here verify my dsm.asm ? Remind that 'im using SDCC (and not Keil).

Another question : Today we have signed our .INF with our PID/VIDs and yyour drivers (before we will add the vitual com port). Do we need to signed it again after changing the descriptos tables to add the VCP ?

Regards

[Pranava_YN]

Hi,

Please share the descriptor file so that we can check it at our end. 

Today we have signed our .INF with our PID/VIDs and your drivers (before we will add the virtual com port). Do we need to signed it again after changing the descriptors tables to add the VCP ?

No modification is required to the existing CYUSB3 INF so the driver signing will still be valid. VCP would require a separate INF file. Refer to the INF file present along with the following Appnote - https://www.cypress.com/documentation/application-notes/an58764-implementing-virtual-com-port-using-...

[JeBo_4132831]

Hi, attached the 2 dscr.scm. The orginal one (dscr_ORI.asm), without the VCP. ANd the one with VCP ...

Regards

[JeBo_4132831]

Hi, if you can help me ... I've attached the DSCR.ASM. Many  Thanks.