A memory card comprising a first modular component that comprises a first
host interface and a first host interface module and a device interface
module configured to operate a device interface that is coupled to a
storage device. The first host interface module is configured to call a
function in the device interface module. The first modular component is
replaceable with a second modular component that comprises a second host
interface and a second host interface module, and the second host
interface module is configured to call the function in the device
interface module.