EP0_RXPKTRDY
csr |= EP0_RXPKTRDY;
csr |= EP0_RXPKTRDY | EP0_SENDSTALL;
if (csr & EP0_RXPKTRDY) {
#define EP0_W1C_BITS (~(EP0_RXPKTRDY | EP0_SETUPPKTRDY | EP0_SENTSTALL))