XC908AS60ACFU Motorola Semiconductor Products, XC908AS60ACFU Datasheet - Page 210

• Manufacturer Part Number: XC908AS60ACFU
• Description: MC68HC908AZ60A, MC68HC908AS60A Hcmos Microcontroller Unit Technical Data
• Manufacturer: Motorola Semiconductor Products

Monitor ROM (MON)
14.4 Functional Description
Technical Data
210
Monitor ROM receives and executes commands from a host computer.
Figure 14-1
communicate with a host computer via a standard RS-232 interface.
While simple monitor commands can access any memory address, the
MC68HC908AS60A and MC68HC908AZ60A have a FLASH security
feature to prevent external viewing of the contents of FLASH. Proper
procedures must be followed to verify FLASH content. Access to the
FLASH is denied to unauthorized users of customer specified software
(see
In monitor mode, the MCU can execute host-computer code in RAM
while all MCU pins except PTA0 retain normal operating mode functions.
All communication between the host computer and the MCU is through
the PTA0 pin. A level-shifting and multiplexing interface is required
between PTA0 and the host computer. PTA0 is used in a wired-OR
configuration and requires a pullup resistor.
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Security
Up to 28.8 kBaud Communication with Host Computer
Execution of Code in RAM or FLASH
FLASH Security
FLASH Programming
shows a sample circuit used to enter monitor mode and
on page 220).
Monitor ROM (MON)
MC68HC908AZ60A — Rev 2.0
MOTOROLA