sc9s08mz16 Freescale Semiconductor, Inc, sc9s08mz16 Datasheet - Page 45

• Manufacturer Part Number: sc9s08mz16
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

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 stop2 or stop3 mode. At power-on, 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.
For compatibility with older M68HC05 MCUs, the HCS08 resets the stack pointer to 0x00FF. In the
SC9S08MZ16, it is usually best to re-initialize the stack pointer to the top of the RAM so the direct page
RAM can be used for frequently accessed RAM variables and bit-addressable program variables. Include
the following 2-instruction sequence in your reset initialization routine (where RamLast is equated to the
highest address of the RAM in the Freescale-provided equate file).
When security is enabled, the RAM is considered a secure memory resource and is not accessible through
BDM or through code executing from non-secure memory. See
description of the security feature.
4.4
The flash memory is intended primarily for program storage. In-circuit programming allows the operating
program to be loaded into the flash memory after final assembly of the application product. It is possible
to program the entire array through the single-wire background debug interface. Because no special
voltages are needed for flash erase and programming operations, in-application programming is also
possible through other software-controlled communication paths. For a more detailed discussion of
in-circuit and in-application programming, refer to the HCS08 Family Reference Manual, Volume I,
Freescale Semiconductor document order number HCS08RMv1.
4.4.1
Features of the flash memory include:
Freescale Semiconductor
•
•
•
•
•
•
•
Flash Size — 16,384 bytes (32 pages of 512 bytes each)
Single power supply program and erase
Command interface for fast program and erase operation
Up to 100,000 program/erase cycles at typical voltage and temperature
Flexible block protection
Security feature for flash and RAM
Auto power-down for low-frequency read accesses
Flash
Features
LDHX
TXS
#RamLast+1
SC9S08MZ16 MCU Data Sheet, Rev. 0 Draft C
;point one past RAM
;SP<-(H:X-1)
Section 4.5,
“Security” for a detailed
Chapter 4 Memory
45