s908az32ag2cfue Freescale Semiconductor, Inc, s908az32ag2cfue Datasheet - Page 123

• Manufacturer Part Number: s908az32ag2cfue
• Description: M68hc08 Microcontrollers 8-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

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.
Freescale Semiconductor
Description
Operand
Data Returned
Opcode
Command Sequence
4.9152MHz
Care should be taken when setting the baud rate since incorrect baud
rate setting can result in communications failure.
4.194MHz
Clock freq
16MHz
32kHz
1MHz
2MHz
4MHz
8MHz
Table 12-9 MC68HC908AZ32A Monitor Baud Rate Selection
Executes RTI instruction
None
None
$28
Table 12-8. RUN (Run User Program) Command
14492.72
28985.51
PTC3=0
1811.59
3623.19
7246.37
7597.83
8904.35
57.97
Baud rate
MC68HC908AZ32A Data Sheet, Rev. 2
SENT TO
MONITOR
14492.75
PTC3=1
ECHO
1811.59
3623.19
3798.91
4452.17
7246.37
905.80
28.98
CAUTION
RUN
Closest PC baud PC
PTC3=0
14400
28800
1800
3600
7200
7680
8861
57.6
RUN
PTC3=1
14400
1800
3600
3840
4430
7200
28.8
900
PTC3=0
0.64
0.64
0.64
0.64
1.08
0.49
0.64
0.64
Error %
PTC3=1
Functional Description
0.63
0.64
0.64
0.64
1.08
0.50
0.64
0.64
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