Monitor ROM (MON)
Technical Data
MC68HC908GP32
•
MC68HC08GP32
—
Rev. 6
204
Monitor ROM (MON)
MOTOROLA
•
IWRITE (indexed write)
•
READSP (read stack pointer)
•
RUN (run user program)
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
READ
READ
ECHO
FROM
HOST
ADDRESS
HIGH
ADDRESS
HIGH
ADDRESS
LOW
ADDRESS
LOW
DATA
RETURN
1
3, 2
1
1
4
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.
4
4
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.
1
1
3
1
1
3
3
3
2, 3
1 = Echo delay, 2 bit times
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..