MC68HC908JL3ECFA Freescale Semiconductor, MC68HC908JL3ECFA Datasheet - Page 79

• Manufacturer Part Number: MC68HC908JL3ECFA
• Description: IC MCU 4K FLASH 8MHZ 48-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908JL3ECFA

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Peripherals: LED, LVD, POR, PWM
• Number Of I /o: 23
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.3 V
• Data Converters: A/D 12x8b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 48-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Connectivity: -

7.4 Security
A security feature discourages unauthorized reading of Flash locations while in monitor mode. The host
can bypass the security feature at monitor mode entry by sending eight security bytes that match the
bytes at locations $FFF6–$FFFD. Locations $FFF6–$FFFD contain user-defined data.
During monitor mode entry, the MCU waits after the power-on reset for the host to send the eight security
bytes on pin PTB0. If the received bytes match those at locations $FFF6–$FFFD, the host bypasses the
security feature and can read all Flash locations and execute code from Flash. Security remains bypassed
until a power-on reset occurs. If the reset was not a power-on reset, security remains bypassed and
security code entry is not required. (See
Freescale Semiconductor
Description
Operand
Data Returned
Opcode
Command Sequence
Description
Operand
Data Returned
Opcode
Command Sequence
SENT TO
MONITOR
SENT TO
MONITOR
ECHO
ECHO
READSP
RUN
Do not leave locations $FFF6–$FFFD blank. For security reasons, program
locations $FFF6–$FFFD even if they are not used for vectors.
Reads stack pointer
None
Returns stack pointer in high byte:low byte order
$0C
Executes RTI instruction
None
None
$28
READSP
Table 7-8. READSP (Read Stack Pointer) Command
RUN
Table 7-9. RUN (Run User Program) Command
MC68HC908JL3E Family Data Sheet, Rev. 4
SP HIGH
Figure
SP LOW
7-7.)
NOTE
RESULT
Security
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