MC908AZ32ACFUE Datasheet, PDF (123/324 Pages) Freescale Semiconductor, Inc – Microcontrollers

Table 12-8. RUN (Run User Program) Command
Description
Executes RTI instruction
Operand
None
Data Returned
None
Opcode
$28
Command Sequence
SENT TO
MONITOR
RUN
RUN
ECHO
Functional Description
12.3.6 Baud Rate
The MC68HC908AZ32A features a monitor mode which is optimised to operate with either a 4.9152 MHz
crystal clock source (or multiples of 4.9152 MHz) or a 4 MHz crystal (or multiples of 4 MHz). This supports
designs which use the MSCAN module, which is generally clocked from a 4 MHz, 8 MHz or 16 MHZ
internal reference clock. The table below outlines the available baud rates for a range of crystals and how
they can match to a PC baud rate.
Table 12-9 MC68HC908AZ32A Monitor Baud Rate Selection
Clock freq
32kHz
1MHz
2MHz
4MHz
4.194MHz
4.9152MHz
8MHz
16MHz
Baud rate
PTC3=0 PTC3=1
57.97
28.98
1811.59
905.80
3623.19 1811.59
7246.37 3623.19
7597.83 3798.91
8904.35 4452.17
14492.72 7246.37
28985.51 14492.75
Closest PC baud PC
PTC3=0 PTC3=1
57.6
28.8
1800
900
3600
1800
7200
3600
7680
3840
8861
4430
14400
7200
28800
14400
Error %
PTC3=0 PTC3=1
0.64
0.63
0.64
0.64
0.64
0.64
0.64
0.64
1.08
1.08
0.49
0.50
0.64
0.64
0.64
0.64
CAUTION
Care should be taken when setting the baud rate since incorrect baud
rate setting can result in communications failure.
MC68HC908AZ32A Data Sheet, Rev. 2
Freescale Semiconductor
123