MC68HC908QY2 MOTOROLA [Motorola, Inc], MC68HC908QY2 Datasheet - Page 122

• Manufacturer Part Number: MC68HC908QY2
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Monitor ROM (MON)
9.4.6 Commands
122
MC68HC908QY4•MC68HC908QT4•MC68HC908QY2•MC68HC908QT2•MC68HC908QY1•MC68HC908QT1
NOTE:
The monitor ROM firmware uses these commands:
The monitor ROM firmware echoes each received byte back to the PTA0
pin for error checking. An 11-bit delay at the end of each command
allows the host to send a break character to cancel the command. A
delay of two bit times occurs before each echo and before READ,
IREAD, or READSP data is returned. The data returned by a read
command appears after the echo of the last byte of the command.
Wait one bit time after each echo before sending the next byte.
3
Notes:
ECHO
Notes:
•
•
•
•
•
•
1 = Echo delay, 2 bit times
2 = Data return delay, 2 bit times
ECHO
4
WRITE
1 = Echo delay, 2 bit times
2 = Cancel command delay, 11 bit times
3 = Wait 1 bit time before sending next byte.
FROM
HOST
FROM
HOST
READ
READ (read memory)
WRITE (write memory)
IREAD (indexed read)
IWRITE (indexed write)
READSP (read stack pointer)
RUN (run user program)
1
1
WRITE
READ
Monitor ROM (MON)
3
ADDRESS
4
HIGH
ADDRESS
Figure 9-7. Read Transaction
Figure 9-8. Write Transaction
HIGH
1
ADDRESS
1
HIGH
ADDRESS
HIGH
3 = Cancel command delay, 11 bit times
4 = Wait 1 bit time before sending next byte.
3
ADDRESS
4
LOW
ADDRESS
LOW
1
ADDRESS
1
LOW
ADDRESS
LOW
3
DATA
3, 2
1
DATA
DATA
MOTOROLA
RETURN
4
2, 3