• MC9S08GB/GT devices are the first members of the HCS08 Family. Because of different hardware
features and FLASH memory allocation, another version of the protocol was required. The
protocol is detected automatically by the latest hc08sprg.exe PC Bootloader software and
becomes invisible to the user.
MC9S08GB/GT MCUs have two SCIs (the SCI channel must be selected at compile time).
These MCUs have no on-chip FLASH programming routines. Therefore, the bootloader must do all
FLASH programming, and this implementation demonstrates this (it has been entirely adopted from
HCS08 Family Reference Manual Volume 1 (Freescale Semiconductor order number HCS08RMv1/D; see
For additional information, refer to these documents from the Freescale Semiconductor website,
• AN2295SW: Contains all of the software files for this application note in a zip file.
• AN2140: Serial Monitor for MC9S08GB/GT