The Section 20.1.1 in the B4860 Reference Manual shows the features of the B4860 eSDHC module:Compatible with the SD memory card specification version 2.0, and supports the high capacity SD memory card.
There is the following information about max capacity for SDHC card in internet:
The Secure Digital High Capacity (SDHC) format, announced in January 2006 and defined in version 2.0 of the SD specification, supports cards with capacities up to 32 GB.
See the following page:
https://en.wikipedia.org/wiki/SD_card
