The R1A is an obsolte revision of the SPB820.
The R1A revision of SPB80P did only support UART as host interface. The R2A support both UART and SPI as host interfaces.
A guide on how to migrate from R1A to R2A revsion of the SPB820 can be downloaded via the link below.
1453-_SPB820P_R1A_to_R2A_Migration.pdf
-- AndersGrahn - 2016-11-22