MC68HC908GR8CDW Freescale Semiconductor, MC68HC908GR8CDW Datasheet - Page 202

• Manufacturer Part Number: MC68HC908GR8CDW
• Description: IC MCU 8K FLASH 8MHZ 28-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GR8CDW

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 17
• Program Memory Size: 7.5KB (7.5K x 8)
• Program Memory Type: FLASH
• Ram Size: 384 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 6x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Monitor ROM (MON)
15.5 Security
Technical Data
202
NOTE:
The MCU executes the SWI and PSHH instructions when it enters
monitor mode. The RUN command tells the MCU to execute the PULH
and RTI instructions. Before sending the RUN command, the host can
modify the stacked CPU registers to prepare to run the host program.
The READSP command returns the incremented stack pointer value,
SP + 1. The high and low bytes of the program counter are at addresses
SP + 5 and SP + 6.
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.
Do not leave locations $FFF6–$FFFD blank. For security reasons, they
should be programmed even if they are not used for vectors.
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, Inc.
For More Information On This Product,
Figure 15-7. Stack Pointer at Monitor Mode Entry
Go to: www.freescale.com
Monitor ROM (MON)
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
MC68HC908GR8 — Rev 4.0
SP + 1
SP + 2
SP + 3
SP + 4
SP + 5
15-8.)
SP
SP + 6
SP + 7
MOTOROLA