MC68HC705X32CFU Freescale Semiconductor, MC68HC705X32CFU Datasheet - Page 111

• 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

7.10
The SCI transmitter allows the user to control a one way synchronous serial transmission. The
SCLK pin is the clock output of the SCI transmitter. No clocks are sent to that pin during start bit
and stop bit. Depending on the state of the LBCL bit (bit 0 of SCCR1), clocks will or will not be
activated during the last valid data bit (address mark). The CPOL bit (bit 2 of SCCR1) allows the
user to select the clock polarity, and the CPHA bit (bit 1 of SCCR1) allows the user to select the
phase of the external clock (see
During idle, preamble and send break, the external SCLK clock is not activated.
These options allow the user to serially control peripherals which consist of shift registers, without
losing any functions of the SCI transmitter which can still talk to other SCI receivers. These options
do not affect the SCI receiver which is independent of the transmitter.
The SCLK pin works in conjunction with the TDO pin. When the SCI transmitter is disabled
(TE = 0), the SCLK and TDO pins go to the high impedance state.
Note:
MC68HC05X16
The LBCL, CPOL and CPHA bits have to be selected before enabling the transmitter to
ensure that the clocks function correctly. These bits should not be changed while the
transmitter is enabled.
Figure 7-8 SCI example of synchronous and asynchronous transmission
SCI synchronous transmission
Freescale Semiconductor, Inc.
MC68HC05X16
For More Information On This Product,
Output port
SERIAL COMMUNICATIONS INTERFACE
SCLK
TDO
RDI
Go to: www.freescale.com
Figure
7-8,
Figure 7-9
Data out
Data in
Data in
Clock
Enable
and
Figure
display driver, etc.)
7-10).
(e.g. shift register,
Asynchronous
(e.g. Modem)
Synchronous
7-9
7