mc9s08qd4 Freescale Semiconductor, Inc, mc9s08qd4 Datasheet - Page 38

• Manufacturer Part Number: mc9s08qd4
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

0xFFAA –
0xFFAC
0xFFAD
0xFFAE
0xFFAF
0xFFB0 –
0xFFB7
0xFFB8 –
0xFFBC
0xFFBD
0xFFBE
0xFFBF
Chapter 4 Memory Map and Register Definition
Provided the key enable (KEYEN) bit is 1, the 8-byte comparison key can be used to temporarily
disengage memory security. This key mechanism can be accessed only through user code running in secure
memory. (A security key cannot be entered directly through background debug commands.) This security
key can be disabled completely by programming the KEYEN bit to 0. If the security key is disabled, the
only way to disengage security is by mass erasing the flash if needed (normally through the background
debug interface) and verifying that flash is blank. To avoid returning to secure mode after the next reset,
program the security bits (SEC01:SEC00) to the unsecured state (1:0).
The ICS factory-trimmed value will be stored in 0xFFAE (bit-0) and 0xFFAF. Development tools, such as
programmers can trim the ICS and the internal temperature sensor (via the ADC) and store the values in
0xFFAD–0xFFAF.
4.4
The MC9S08QD4 series includes static RAM. The locations in RAM below 0x0100 can be accessed using
the more efficient direct addressing mode, and any single bit in this area can be accessed with the bit
manipulation instructions (BCLR, BSET, BRCLR, and BRSET). Locating the most frequently accessed
program variables in this area of RAM is preferred.
The RAM retains data when the MCU is in low-power wait, stop2, or stop3 mode. At power-on or after
wakeup from stop1, the contents of RAM are uninitialized. RAM data is unaffected by any reset provided
that the supply voltage does not drop below the minimum value for RAM retention (V
38
Address
Reserved
Reserved for
ADCRL of AD26
value during ICS
trim
Reserved for
ADCRH of AD26
value during ICS
trim and ICS Trim
value “FTRIM”
Reserved for
ICS Trim value
“TRIM”
NVBACKKEY
Reserved
NVPROT
Unused
NVOPT
RAM
Register Name
KEYEN
ADR7
ADR9
Bit 7
—
—
—
—
—
Table 4-4. Nonvolatile Register Summary
MC9S08QD4 Series MCU Data Sheet, Rev. 3
FNORED
ADR6
ADR8
—
—
—
—
—
6
ADR5
—
—
—
—
—
—
5
0
8-Byte Comparison Key
ADR4
FPS
—
—
—
—
—
—
4
0
TRIM
ADR3
—
—
—
—
—
—
3
0
ADR2
—
—
—
—
—
—
2
0
Freescale Semiconductor
RAM
SEC01
ADR1
—
—
—
—
—
—
1
).
SEC00
FTRIM
FPDIS
ADR0
Bit 0
—
—
—
—
—