11.4 External Memory Access

The MPLAB XC32 toolchain provides a more general interface to what is known as external memory, although as will be seen, the memory does not have to be external.

The toolchain needs to learn about external memories that are being attached; however, the compiler does not know how to access these memories. A mechanism is provided by which an application can specify how such memories should be accessed.

Addresses of external objects are all 32 bits in size. The largest attachable memory is 64K (16 bits); the other 16 bits in the address is used to uniquely identify the memory. A total of 64K (16 bits) of these may be (theoretically) attached.

To use this feature, work through the following sections.