Editing AVR microcontrollers (section)

==== Program memory ====
Program instructions are stored in [[non-volatile]] [[flash memory]]. Although the [[Microcontroller unit|MCUs]] are 8-bit, each instruction takes one or two 16-bit words. The size of the program memory is usually indicated in the naming of the device itself (e.g., the ATmega64x line has 64&nbsp;KB of flash, while the ATmega32x line has 32&nbsp;KB). There is no provision for off-chip program memory; all code executed by the AVR core must reside in the on-chip flash. However, this limitation does not apply to the AT94 FPSLIC AVR/FPGA chips.