Based on a uniform processor core derived from the Motorola 6800 , Motorola developed the 68HC05 into a family with over 250 variants. The 6805 family was replaced by the 68HC05 based on the CMOS process .
The 68HC05 microcontrollers exist in variants with ROM , EPROM and Flash memory and with a wide variety of peripheral equipment. Some of the chips are still produced by Freescale today, as these chips were often used in industrial applications that are produced over very long periods of time. New chips based on the 68HC05 have not been developed for several years, the 68HC05 family has been replaced by the 68HC08 family.
The different variants of the 68HC05 are identified by a letter / number combination appended to the "MC68HC05", which in some cases also indicates that it belongs to a subfamily. In addition, the variant of the program memory is indicated by the fact that chips with ROM are designated as "MC68HC05xxx", those with EPROM as "MC68HC705xxx" and with FLASH as "MC68HC805xxx". The MC68HC705C8A is a relatively common chip with EPROM.
In addition to Motorola, Hitachi also produced some variants of the 68HC05.