MC56F8257MLH Freescale Semiconductor, MC56F8257MLH Datasheet - Page 618

• Manufacturer Part Number: MC56F8257MLH
• Description: DSC 64K FLASH 60MHZ 64-LQFP
• Manufacturer: Freescale Semiconductor
• Series: 56F8xxxr

Specifications of MC56F8257MLH

• Core Processor: 56800E
• Core Size: 16-Bit
• Speed: 60MHz
• Connectivity: CAN, I²C, LIN, SCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Ram Size: 4K x 16
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 16x12b, D/A 1x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 64-LQFP
• Product: DSCs
• Processor Series: 56800E
• Core: 56800E
• Device Million Instructions Per Second: 60 MIPs
• Maximum Clock Frequency: 60 MHz
• Number Of Programmable I/os: 54
• Data Ram Size: 8 KB
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12 bit, 8 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

Functional Description
20.3.10 Flash Security Operation
Flash security provides a means to protect the embedded code within the flash array from
unauthorized external access. The state of flash security is reflected in the state of the
SECSTAT bit in the security register high. The value of the SECSTAT bit at reset is
determined by the values in the security words stored in the flash configuration field.
Thus, by appropriately programming the configuration field, the part can be forced into
secure mode at reset or power-up.
Flash security prevents unauthorized external access by the JTAG/EOnCE port. After
flash security is set, an external user is unable to view or change embedded software and
is thus unable to introduce code sequences to undo security or export code.
There are three methods of disabling flash security at run time:
Only the first method preserves the contents of flash memory.
20.3.10.1 Set Flash Security
The user can secure the device by programming the security code 10b into the program
memory location 0x00_7FF7. The nonvolatile security word ensures the device remains
secure after a reset.
20.3.10.2 Back Door Access
The following directions explain how to disable flash security at run-time. This method is
the only one for disabling security without the erasure of flash contents. The KEYEN bit
in the security register high must be set to enable back-door key access.
If all four words written match the flash content in the configuration field, security is
bypassed until the next reset.
After the next reset sequence, the device is secured again.
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1. Execute a back door access scheme built into the application.
2. Pass an erase-verify check.
3. Execute the JTAG lockout-recovery routine to mass erase the flash .
1. Set the KEYACC bit in the configuration register.
2. Write the correct 4-word (64-bit) back-door comparison key to the back-door key
3. Clear the KEYACC bit.
locations (0x7FFC to 0x7FFF) of the flash memory configuration field. The four
write cycles can be separated by any number of other operations.
MC56F825x/4x Reference Manual, Rev. 2, 10/2010
Preliminary
Freescale Semiconductor