Giangiacomo Zaffini

68HC11 operative frequencies

Discussion created by Giangiacomo Zaffini on Aug 22, 2012
Latest reply on Aug 22, 2012 by Giangiacomo Zaffini

Happy to introduce myself with this simple question :smileytongue:


As far as this 68hc11 brief profile says


The 68HC11E family MCUs all combine the M68HC11 CPU with high-performance, on-chip peripherals. The E series is comprised of many devices with various configurations of RAM, ROM or EPROM, and EEPROM. Several low-voltage devices are also available. With the exception of a few minor differences, the operation of all E-series MCUs is identical. A fully static design and high-density complementary metal-oxide semiconductor (HCMOS) fabrication process allow E-series devices to operate at frequencies from 3 MHz to dc.


[taken from




My question is the following:


given a designed board with external crystal running @ 8Mhz and MC68HC11E1CFNE2 working with Eclock @ E 2Mhz,


whenever I have to switch MCU on the socket for this board with a different MC68HC11E1CFNE3 (note the very last number),


is it guaranteed that  external crystal running @ 8Mhz does good for a Eclock @ E 2Mhz and so there is not any impact on software application?