DESCRIPTION
In-System Programming (ISP) allows the user to download new code while the microcontroller sits in the application. In-Application Programming (IAP) means that the microcontroller fetches new program code and reprograms itself while in the system. A default serial loader (boot loader) program in ROM allows serial In-System programming of the Flash memory via the UART without the need for a loader in the Flash code. For In-Application Programming, the user program erases and reprograms the Flash memory by use of standard routines contained in ROM. The dev ice supports 6-c loc k/12-c loc k mode selec tion by programming a Flas h bit using parallel programming or In-Sy stem Programming. In addition, an SFR bit (X2) in the cloc k control regis ter (CKCON) als o selec ts between 6-c lock/12-c lock mode. Additionally, when in 6-clock mode, peripherals may use either 6 clocks per machine cycle or 12 clocks per machine cycle. This choice is available individually for each peripheral and is selected by bits in the CKCON register.
Philips
