MC68HC705X32CFU Freescale Semiconductor, MC68HC705X32CFU Datasheet - Page 122

• Manufacturer Part Number: MC68HC705X32CFU
• Manufacturer: Freescale Semiconductor

Specifications of MC68HC705X32CFU

• Cpu Family: HC05
• Device Core Size: 8b
• Frequency (max): 4MHz
• Interface Type: SCI
• Program Memory Type: EPROM
• Program Memory Size: 32KB
• Total Internal Ram Size: 528Byte
• # I/os (max): 32
• Number Of Timers - General Purpose: 1
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4.5V
• On-chip Adc: 8-chx8-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 64
• Package Type: PQFP
• Lead Free Status / Rohs Status: Supplier Unconfirmed

7
7.12
The flexibility of the baud rate generator allows many different baud rates to be selected, depending
on the CPU clock frequency. A particular baud rate may be generated by manipulating the various
prescaler and division ratio bits.
can be achieved for five typical crystal frequencies, for each of the CPU clock frequency options and
only using the prescaler bits.
obtained using a further division ratio provided by the SCI rate select bits. Note that the five
examples given in
Note:
The clock in the ‘Clock divided by’ column refers to the internal processor clock.
Table 7-8 SCI baud rate selection with CPU clock frequency = f
Table 7-6 SCI baud rate selection with CPU clock frequency = f
Table 7-7 SCI baud rate selection with CPU clock frequency = f
Baud rate selection
SCP1
SCP1
SCP1
0
0
1
1
0
0
1
1
0
0
1
1
Table 7-9
Freescale Semiconductor, Inc.
SCP0
SCP0
SCP0
For More Information On This Product,
0
1
0
1
0
1
0
1
0
1
0
1
SERIAL COMMUNICATIONS INTERFACE
are representative samples only.
Table 7-9
divided
divided
divided
Table
Clock
Clock
Clock
by
13
by
13
by
13
1
3
4
1
3
4
1
3
4
Go to: www.freescale.com
7-6,
4.194304
shows how lower transmitter or receiver baud rates may be
131072
125000
125000
43691
32768
10082
41667
31250
41667
31250
16.00
20.00
9600
9600
Table 7-7
Crystal frequency – f
Crystal frequency – f
Crystal frequency – f
125000
115200
18.432
41667
31250
62500
20833
15625
38400
28800
9600
4800
8861
4.00
8.00
and
Table 7-8
2.4576
4.9152
76800
25600
19200
38400
12800
62500
20833
15625
10.00
5907
9600
2954
4800
osc
osc
osc
4.194304
show the highest baud rates that
62500
20833
15625
32768
10082
38400
12800
6.144
4800
8192
2521
9600
2954
(MHz)
2.00
(MHz)
(MHz)
1.8432
2.4576
57600
19200
14400
19200
14400
31250
10417
4430
4430
1477
7813
2400
5.0
OSC
OSC
OSC
/10
MC68HC05X16
/2
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Rev. 1