MC68HC705X32CFU Freescale Semiconductor, MC68HC705X32CFU Datasheet - Page 121

• 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

SCR2, SCR1, SCR0 — SCI rate select bits (receiver)
These three read/write bits select the baud rates for the receiver. The prescaler output described
above is divided by the factors shown in
The following equations are used to calculate the receiver and transmitter baud rates:
where:
MC68HC05X16
NP = prescaler divide ratio
NT = transmitter baud rate divide ratio
NR = receiver baud rate divide ratio
baudTx = transmitter baud rate
baudRx = receiver baud rate
f
CLK
= CPU clock frequency
Freescale Semiconductor, Inc.
For More Information On This Product,
Table 7-5 Second prescaler stage (receiver)
SERIAL COMMUNICATIONS INTERFACE
SCR2
0
0
0
0
1
1
1
1
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baudRx
baudTx
SCR1
0
0
1
1
0
0
1
1
Table
=
=
7-5.
SCR0
-----------------------------------
16 NP NR
-----------------------------------
16 NP NR
0
1
0
1
0
1
0
1
f
f
clk
clk
division ratio (NR)
Receiver
128
16
32
64
1
2
4
8
7-19
7