A memory component and a controller communicate commands and data with each other The commands to activate and then access data, and the data itself, are all communicated between a controller and the memory component at different times. The controller and memory component each calculate a respective error detecting code (EDC) values on the activate command information (e.g., bank address and row address) and store them indexed by the bank address. When the memory component is accessed, retrieved EDC values are combined with EDC values calculated from the access command information, and the data itself. The memory component transmits its combined EDC value to the controller for checking.