MC68HC908GT16_07 Datasheet, PDF (46/292 Pages) Freescale Semiconductor, Inc – Microcontrollers

Memory
Table 2-2. Examples of Protect Address Ranges
BPR[7:0]
$00
$01 (0000 0001)
$02 (0000 0010)
$03 (0000 0011)
$04 (0000 0100)
$FC (1111 1100)
$FD (1111 1101)
$FE (1111 1110)
$FF
Addresses of Protect Range
The entire Flash memory is protected.
$C040 (1100 0000 0100 0000) — $FFFF
$C080 (1100 0000 1000 0000) — $FFFF
$C0C0 (1100 0000 1100 0000) — $FFFF
$C100 (1100 0001 0000 0000) — $FFFF
and so on...
$FF00 (1111 1111 0000 0000) — FFFF
$FF40 (1111 1111 0100 0000) — $FFFF
FLBPR and vectors are protected
$FF80 (1111 1111 1000 0000) — FFFF
Vectors are protected
The entire Flash memory is not protected.
2.6.8 ICG User Trim Registers (ICGTR5 and ICGTR3)
The ICG user trim register are two normal bytes of Flash memory which are allocated for the user to store
copies of the ICG trim register (ICGTR) value. ICGTR5 is allocated for storage of the trim value when a
5-V supply is used, ICGTR3 for storage of the trim value when a 3-V supply is used. Representative trim
values are programmed into these locations by Freescale but they may be erased and reprogrammed by
the user at any time.
Storage and retrieval of data in these registers is not automatic and must be performed programmatically.
Typically, these locations are programmed by the user during an in-system calibration procedure and one
of them, depending on the application supply voltage, is subsequently used by the user’s initialization
code to configure the ICG each time following a reset.
ICGTR5 is used by the MC68HC908GT16 monitor ROM program during its initialization sequence if
monitor mode was entered while clocking from the ICG. If the contents of ICGTR5 are not $FF then the
contents are copied to ICGTR.
NOTE
The contents of ICGTR3 are not utilized by the monitor ROM program.
Address: ICGTR5, $FF80 and ICGTR3, $FF81
Bit 7
6
5
4
3
2
1
Bit 0
Read:
TRIM7
Write:
TRIM6
TRIM5
TRIM4
TRIM3
TRIM2
TRIM1
TRIM0
Reset:
Unaffected by reset. Initial value from factory is 1.
Write to this register is by a programming sequence to the Flash memory.
Figure 2-7. ICG User Trim Registers (ICGTR5 and ICGTR3)
TRIM[7:0] — ICG Trim Factor Bits
These bits are copied by the monitor ROM program following a reset, if monitor mode was entered
while clocking from the ICG and may be copied by the user’s initialization code to the ICG trim register
(ICGTR).
MC68HC908GT16 • MC68HC908GT8 • MC68HC08GT16 Data Sheet, Rev. 5.0
46
Freescale Semiconductor