SNLS551B November 2017 – November 2018 DP83TC811R-Q1
PRODUCTION DATA.
xMII Loopback is the shallowest loop through the PHY. It is a useful test mode to validate communications between the MAC and the PHY. When in xMII Loopback, data transmitted from a connected MAC on the TX path is internally looped back in the DP83TC811R-Q1 to the RX pins where it can be checked by the MAC. There is no link indication when in xMII loopback.
xMII Loopback is enabled by setting bit[14] in the BMCR Register 0x0000 – Basic Mode Control Register.