ZHCSAB9E September 2012 – June 2019 DP83848-EP
PRODUCTION DATA.
When enabled, this function uses Auto-Negotiation to determine the proper configuration for transmission and reception of data and subsequently selects the appropriate MDI pair for MDI/MDIX operation. The function uses a random seed to control switching of the crossover circuitry. This implementation complies with the corresponding IEEE 802.3 Auto-Negotiation and Crossover Specifications.
Auto-MDIX is enabled by default and can be configured via strap or via PHYCR (19h) register, bits [15:14].
Neither Auto-Negotiation nor Auto-MDIX is required to be enabled in forcing crossover of the MDI pairs. Forced crossover can be achieved through the FORCE_MDIX bit, bit 14 of PHYCR (19h) register.
Note: Auto-MDIX will not work in a forced mode of operation.