Editing PIC microcontrollers (section)

===Code space===
The code space is generally implemented as on-chip [[Read-only memory|ROM]], [[EPROM]] or [[flash ROM]]. In general, there is no provision for storing code in external memory due to the lack of an external memory interface. The exceptions are PIC17 and select high pin count PIC18 devices.<ref>{{cite web |title=AN869: External Memory Interfacing Techniques for the PIC18F8XXX |url=http://ww1.microchip.com/downloads/en/AppNotes/00869b.pdf |first=Tim |last=Rovnak |publisher=Microchip Technology |year=2003 |id=DS00869B |access-date=24 August 2009}}</ref>