MC908GR8CDWE Datasheet, PDF (198/408 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Freescale Semiconductor, Inc.
Monitor ROM (MON)
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.
FROM
HOST
READ
READ
ADDRESS ADDRESS ADDRESS ADDRESS
HIGH
HIGH
LOW
LOW
4
1
4
1
4
1
3, 2
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.
Figure 15-5. Read Transaction
DATA
4
RETURN
FROM
HOST
WRITE
WRITE
ADDRESS ADDRESS ADDRESS ADDRESS
HIGH
HIGH
LOW
LOW
DATA
DATA
3
1
3
1
3
1
3
1
2, 3
ECHO
Notes:
1 = Echo delay, 2 bit times
2 = Cancel command delay, 11 bit times
3 = Wait 1 bit time before sending next byte.
Figure 15-6. Write Transaction
Technical Data
198
MC68HC908GR8 — Rev 4.0
Monitor ROM (MON)
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MOTOROLA