usb_selftest_dfu Directory Reference

Directory dependency graph for usb_selftest_dfu:

Directories
	inc
	src

Detailed Description

The control-transfer member of the USB self-loop matrix: host DFU_DNLOAD -> device capture -> host DFU_UPLOAD -> byte-exact compare, through a real DFU class. The two USB ports are cabled to each other and one image runs both stacks – USBFS (J11) is a ThreadX + USBX DFU class started directly in dfuIDLE (class 0xFE / subclass 0x01 / protocol 0x02), USBHS (J7) a polled DFU host on the first-party ra8_usb_host_* primitives. It is the on-bench evidence that the device EP0 control-OUT data stage works; each block is one full 64-byte control data stage, MPS-exact against a single DCP bank.

The download closes with DFU_ABORT rather than the spec's zero-length manifest DFU_DNLOAD: this USBX DFU class is not manifestation-tolerant, so after MANIFEST it parks in dfuMANIFEST-WAIT-RESET and only a USB bus reset returns it to a usable state – which would tear down the in-place UPLOAD round trip. DFU_ABORT gets back to dfuIDLE with no reset.

Why the control-OUT receive is split across two interrupts

A control-WRITE data stage cannot be received synchronously in the SETUP ISR: the FS device ISR and the lower-priority HS host worker share one CPU, so a blocking receive spins out the very thread that has to send the data – a same-CPU deadlock. The SETUP ISR instead arms the DCP (ra8_usb_dcp_out_arm) and returns; the following DCP BRDY IRQ drains the bank (ra8_usb_dcp_out_read) and only then runs the chapter-9 dispatcher.

Two register details go with it. On the host the DCP must set DCPCFG.DIR = 1 for an OUT data stage, because the default issues IN tokens. On the device, driving DCPCTR.SQSET (DATA1) and clearing a stale CCPL before arming is what makes the SIE accept the data instead of flagging CTSQ = SQER.

Pinout

FS device: P4_07 VBUS sense, P5_00 VBUSEN GPIO LOW, P8_14/P8_15 data (PSEL usb_fs). HS host: SW4-8 Host via the U15 expander, PD07 HIGH (U18 powers J7), P4_08 VBUS sense (PSEL usb_hs). Console: PD_02/PD_03 SCI8. The device advertises VID 0x1209 with a per-app PID; bench use only.