i.MX RT1020 Processor Reference Manual, Rev. 1, 12/2018
22.214.171.124 SDRAM control register 2 (SDRAMCR2)
ACT2ACT and REF2REF fields do not specify the units. It's almost certainly cycles, but it should be specified.
Also some fields refer to 'Prescaler period' whereas the actual field (PRESCALE) refers to it as 'Prescaler timer period'. That ought to be made consistent please.