MC9S08QG4MPAE Freescale Semiconductor, MC9S08QG4MPAE Datasheet - Page 54

• Manufacturer Part Number: MC9S08QG4MPAE
• Description: IC MCU 4K FLASH 8-PDIP
• Manufacturer: Freescale Semiconductor
• Series: HCS08r

Specifications of MC9S08QG4MPAE

• Core Processor: HCS08
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 4
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• Controller Family/series: HCS08
• No. Of I/o's: 6
• Ram Memory Size: 256Byte
• Cpu Speed: 20MHz
• No. Of Timers: 2
• Embedded Interface Type: I2C, SCI, SPI
• Rohs Compliant: Yes
• Processor Series: S08QG
• Core: HCS08
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: I2C, SCI, SPI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 1
• Maximum Operating Temperature: + 125 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: EWS08
• Development Tools By Supplier: DEMO9S08QG8E
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

Chapter 4 Memory Map and Register Definition
must be programmed to logic 0 to enable block protection. Therefore the value 0xF8 must be programmed
into NVPROT to protect addresses 0xFA00 through 0xFFFF.
One use for block protection is to block protect an area of FLASH memory for a bootloader program. This
bootloader program then can be used to erase the rest of the FLASH memory and reprogram it. Because
the bootloader is protected, it remains intact even if MCU power is lost in the middle of an erase and
reprogram operation.
4.5.7
Whenever any block protection is enabled, the reset and interrupt vectors will be protected. Vector
redirection allows users to modify interrupt vector information without unprotecting bootloader and reset
vector space. Vector redirection is enabled by programming the FNORED bit in the NVOPT register
located at address 0xFFBF to zero. For redirection to occur, at least some portion but not all of the FLASH
memory must be block protected by programming the NVPROT register located at address 0xFFBD. All
of the interrupt vectors (memory locations 0xFFC0–0xFFFD) are redirected, though the reset vector
(0xFFFE:FFFF) is not.
For example, if 512 bytes of FLASH are protected, the protected address region is from 0xFE00 through
0xFFFF. The interrupt vectors (0xFFC0–0xFFFD) are redirected to the locations 0xFDC0–0xFDFD. Now,
if an SPI interrupt is taken for instance, the values in the locations 0xFDE0:FDE1 are used for the vector
instead of the values in the locations 0xFFE0:FFE1. This allows the user to reprogram the unprotected
portion of the FLASH with new program code including new interrupt vector values while leaving the
protected area, which includes the default vector locations, unchanged.
4.6
The MC9S08QG8/4 includes circuitry to prevent unauthorized access to the contents of FLASH and RAM
memory. When security is engaged, FLASH and RAM are considered secure resources. Direct-page
registers, high-page registers, and the background debug controller are considered unsecured resources.
Programs executing within secure memory have normal access to any MCU memory locations and
resources. Attempts to access a secure memory location with a program executing from an unsecured
memory space or through the background debug interface are blocked (writes are ignored and reads return
all 0s).
Security is engaged or disengaged based on the state of two nonvolatile register bits (SEC01:SEC00) in
the FOPT register. During reset, the contents of the nonvolatile location NVOPT are copied from FLASH
into the working FOPT register in high-page register space. A user engages security by programming the
NVOPT location which can be done at the same time the FLASH memory is programmed. The 1:0 state
disengages security and the other three combinations engage security. Notice the erased state (1:1) makes
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Security
Vector Redirection
FPS7 FPS6 FPS5 FPS4 FPS3 FPS2 FPS1
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MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 5
Figure 4-4. Block Protection Mechanism
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