Datasheet

Monitor ROM (MON)
Technical Data MC68HC908GR8 — Rev 4.0
198 Monitor ROM (MON) MOTOROLA
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.
NOTE: Wait one bit time after each echo before sending the next byte.
Figure 15-5. Read Transaction
Figure 15-6. Write Transaction
READREAD
ECHO
FROM
HOST
ADDRESS
HIGH
ADDRESS
HIGH
ADDRESS
LOW
ADDRESS
LOW
DATA
RETURN
13, 2114
4
Notes:
2 = Data return delay, 2 bit times
3 = Cancel command delay, 11 bit times
4 = Wait 1 bit time before sending next byte.
44
1 = Echo delay, 2 bit times
WRITE
WRITE
ECHO
FROM
HOST
ADDRESS
HIGH
ADDRESS
HIGH
ADDRESS
LOW
ADDRESS
LOW
DATA
DATA
Notes:
2 = Cancel command delay, 11 bit times
3 = Wait 1 bit time before sending next byte.
113113
3
32, 3
1 = Echo delay, 2 bit times
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
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