For applications requiring higher throughput or direct access to the hardware (like bit-banging the CBUS pins), FTDI provides the D2XX driver.
The driver maps the UART status registers to the USB protocol. ftr232r usb uart driver
In the mid-2010s, FTDI updated their drivers to detect counterfeit FTR232R chips. If a clone chip was detected, the driver would set the PID to 0x0000 , effectively "bricking" the device software-wise. This highlighted the tight coupling between the driver's verification logic and the hardware's internal acknowledgement sequences. This caused significant issues in the supply chain and required rollbacks of specific driver versions. ftr232r usb uart driver