mc68hc908sr12 Freescale Semiconductor, Inc, mc68hc908sr12 Datasheet - Page 174

• Manufacturer Part Number: mc68hc908sr12
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Monitor ROM (MON)
Data Sheet
174
NOTE:
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
ECHO
Notes:
•
•
•
ECHO
Notes:
4
WRITE
1 = Echo delay, 2 bit times
FROM
HOST
2 = Cancel command delay, 11 bit times
3 = Wait 1 bit time before sending next byte.
1 = Echo delay, 2 bit times
2 = Data return delay, 2 bit times
3 = Cancel command delay, 11 bit times
4 = Wait 1 bit time before sending next byte.
FROM
HOST
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 10-5. Read Transaction
Figure 10-6. Write Transaction
HIGH
1
ADDRESS
1
HIGH
ADDRESS
HIGH
MC68HC908SR12•MC68HC08SR12 — Rev. 5.0
3
ADDRESS
4
LOW
ADDRESS
LOW
1
ADDRESS
1
LOW
ADDRESS
LOW
3
DATA
Freescale Semiconductor
3, 2
1
DATA
DATA
RETURN
4
2, 3