MC908QT1 FREESCALE [Freescale Semiconductor, Inc], MC908QT1 Datasheet - Page 145

• Manufacturer Part Number: MC908QT1
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

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.
A brief description of each monitor mode command is given in
Freescale Semiconductor
Data Returned
3
Wait one bit time after each echo before sending the next byte.
Notes:
SENT TO MONITOR
ECHO
Notes:
Description
1 = Echo delay, 2 bit times
2 = Data return delay, 2 bit times
WRITE
ECHO
1 = Echo delay, 2 bit times
2 = Cancel command delay, 11 bit times
3 = Wait 1 bit time before sending next byte.
ECHO
4
FROM
HOST
Operand
Opcode
FROM
HOST
READ
READ
1
WRITE
1
READ
READ
Table 15-3. READ (Read Memory) Command
Read byte from memory
2-byte address in high-byte:low-byte order
Returns contents of specified address
$4A
3
ADDRESS
MC68HC908QY/QT Family Data Sheet, Rev. 5
4
HIGH
ADDRESS
ADDRESS
Figure 15-15. Read Transaction
Figure 15-16. Write Transaction
HIGH
HIGH
1
ADDRESS
1
Command Sequence
HIGH
ADDRESS
ADDRESS
HIGH
HIGH
3 = Cancel command delay, 11 bit times
4 = Wait 1 bit time before sending next byte.
3
ADDRESS
NOTE
4
LOW
ADDRESS
ADDRESS
LOW
LOW
1
ADDRESS
1
LOW
ADDRESS
ADDRESS
LOW
LOW
Table 15-3
3
DATA
3, 2
1
through
DATA
DATA
DATA
Table
RETURN
RETURN
4
2, 3
Monitor Module (MON)
15-8.
145