MC908AP32CFBE Freescale, MC908AP32CFBE Datasheet - Page 125

• Manufacturer Part Number: MC908AP32CFBE
• Manufacturer: Freescale

Specifications of MC908AP32CFBE

• Cpu Family: HC08
• Device Core Size: 8b
• Frequency (max): 8MHz
• Interface Type: SCI/SPI
• Total Internal Ram Size: 2KB
• # I/os (max): 32
• Number Of Timers - General Purpose: 4
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 44
• Package Type: PQFP
• Program Memory Type: Flash
• Program Memory Size: 32KB
• Lead Free Status / RoHS Status: Compliant

8.4 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 PTA0. 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
PTA0
RST
V
NOTES:
Do not leave locations $FFF6–$FFFD blank. For security reasons, program
locations $FFF6–$FFFD even if they are not used for vectors.
DD
1 = Echo delay, 2 bit times.
2 = Data return delay, 2 bit times.
4 = Wait 1 bit time before sending next byte.
Figure 8-7. Stack Pointer at Monitor Mode Entry
FROM HOST
FROM MCU
4096 + 32 ICLK CYCLES
Figure 8-8. Monitor Mode Entry Timing
MC68HC908AP Family Data Sheet, Rev. 4
HIGH BYTE OF PROGRAM COUNTER
LOW BYTE OF PROGRAM COUNTER
HIGH BYTE OF INDEX REGISTER
LOW BYTE OF INDEX REGISTER
CONDITION CODE REGISTER
ACCUMULATOR
Figure
1
256 BUS CYCLES (MINIMUM)
NOTE
4
8-8.)
1
SP
SP + 1
SP + 2
SP + 3
SP + 4
SP + 5
SP + 6
SP + 7
1
2
4
1
Security
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