diff --git a/src/portable/st/synopsys/dcd_synopsys.c b/src/portable/st/synopsys/dcd_synopsys.c index 03c33c598..283fefd01 100644 --- a/src/portable/st/synopsys/dcd_synopsys.c +++ b/src/portable/st/synopsys/dcd_synopsys.c @@ -365,6 +365,13 @@ static void edpt_schedule_packets(uint8_t rhport, uint8_t const epnum, uint8_t c ((total_bytes << USB_OTG_DIEPTSIZ_XFRSIZ_Pos) & USB_OTG_DIEPTSIZ_XFRSIZ_Msk); in_ep[epnum].DIEPCTL |= USB_OTG_DIEPCTL_EPENA | USB_OTG_DIEPCTL_CNAK; + // For ISO endpoint set correct odd/even bit for next frame. + if ((in_ep[epnum].DIEPCTL & USB_OTG_DIEPCTL_EPTYP) == USB_OTG_DIEPCTL_EPTYP_0) + { + // Take odd/even bit from frame counter. + uint32_t const odd_frame_now = (dev->DSTS & (1u << USB_OTG_DSTS_FNSOF_Pos)); + in_ep[epnum].DIEPCTL |= (odd_frame_now ? USB_OTG_DIEPCTL_SD0PID_SEVNFRM_Msk : USB_OTG_DIEPCTL_SODDFRM_Msk); + } // Enable fifo empty interrupt only if there are something to put in the fifo. if(total_bytes != 0) { dev->DIEPEMPMSK |= (1 << epnum);