mc68hc908kx8 Freescale Semiconductor, Inc, mc68hc908kx8 Datasheet - Page 178

• Manufacturer Part Number: mc68hc908kx8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Development Support
16.3.1.10 Commands
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.
178
•
•
•
•
•
•
READ, read memory
WRITE, write memory
IREAD, indexed read
IWRITE, indexed write
READSP, read stack pointer
RUN, run user program
4
Wait one bit time after each echo before sending the next byte.
ECHO
Notes:
4
ECHO
Notes:
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.
WRITE
1 = Echo delay, 2 bit times
3 = Cancel command delay, 11 bit times
4 = Wait 1 bit time before sending next byte.
READ
FROM
HOST
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
FROM
HOST
1
1
WRITE
READ
4
4
ADDRESS
ADDRESS
HIGH
HIGH
Figure 16-12. Read Transaction
Figure 16-13. Write Transaction
1
1
ADDRESS
ADDRESS
HIGH
HIGH
4
4
ADDRESS
NOTE
ADDRESS
LOW
LOW
1
1
ADDRESS
ADDRESS
LOW
LOW
4
DATA
3, 2
1
DATA
DATA
RETURN
4
Freescale Semiconductor
3, 4