Datasheet

MC9S08GB60A Data Sheet, Rev. 2
Freescale Semiconductor 283
Appendix B
EB652: Migrating from the GB60 Series to the GB60A Series
The following text was taken from Freescale Semiconductor document EB652. It is copied here for your
conveninece. Please see EB652 at freescale.com for the must up-to-date information regarding “Migrating
from the GB60 series to the GB60A series.”
B.1 Overview
This document will explain the differences to be aware of when migrating from the MC9S08GB60,
MC9S08GB32, MC9S08GT60, and MC9S08GT32 devices to the MC9S08GB60A, MC9S08GB32A,
MC9S08GT60A and MC9S08GT32A devices. For the remainder of this document, GB60 series will refer
to the original non-”A” devices and GB60A series will refer to the newer “A” suffix devices.
Much of the functionality and performance of the GB60 series and the GB60A series will be identical.
However, there are several differences designers should understand when migrating to the GB60A series.
B.2 Flash Programming Voltage
The GB60 series has a minimum V
DD
requirement for erasing and programming the flash, equal to 2.1 V.
The GB60A series eliminates this minimum V
DD
requirement. On the GB60A series, the flash can be
programmed and erased across the full operating voltage range of the MCU, or 1.8 V to 3.6 V.
B.3 Flash Block Protection: 60K Devices Only
The GB/GT60 flash block protection has a redundant setting. On the GB/GT60A, the redundant setting is
used to add a new protection option.
On the GB/GT60, when protection is enabled by setting the FPDIS bit, setting the FPS2:FPS1:FPS0 bits
to 1:1:1 protects the same range as 1:1:0, which is locations $8000 to $FFFF.
On the GB/GT60A, setting the FPS2:FPS1:FPS0 bits to 1:1:0, protects the same range as on the GB/GT60.
However, setting the bits to 1:1:1 protects locations $182C to $FFFF, leaving locations $1080 to $17FF
open to reprogramming.
This new protection option is useful for protecting the main user program area while leaving a small
section of 1920 bytes available for data storage.
B.4 Internal Clock Generator: High Gain Oscillator Option
The GB60 series only has a low-power external oscillator, designed for the low current consumption. The
GB60A series has a second external oscillator option: a high gain external oscillator which provides