CM68HC05C4ACFB Motorola / Freescale Semiconductor, CM68HC05C4ACFB Datasheet - Page 65
![no-image](/images/no-image-200.jpg)
CM68HC05C4ACFB
Manufacturer Part Number
CM68HC05C4ACFB
Description
Microcontroller
Manufacturer
Motorola / Freescale Semiconductor
Datasheet
1.CM68HC05C4ACFB.pdf
(156 pages)
- Current page: 65 of 156
- Download datasheet (649Kb)
9.5 SCI Operation
9.5.1 Transmitter
9.5.1.1 Character Length
9.5.1.2 Character Transmission
MC68HC05C4A
MOTOROLA
—
Rev. 4.0
The SCI allows full-duplex, asynchronous, RS232 or RS422 serial
communication between the MCU and remote devices, including other
MCUs. The SCI’s transmitter and receiver operate independently,
although they use the same baud-rate generator. The following
paragraphs describe the operation of the SCI transmitter and receiver.
Figure 9-2
The transmitter can accommodate either 8-bit or 9-bit data. The state of
the M bit in SCI control register 1 (SCCR1) determines character length.
When transmitting 9-bit data, bit T8 in SCCR1 is the ninth bit (bit 8).
During transmission, the transmit shift register shifts a character out to
the PD1/TDO pin. The SCI data register (SCDR) is the write-only buffer
between the internal data bus and the transmit shift register.
Writing a logic 1 to the TE bit in SCI control register 2 (SCCR2) and then
writing data to the SCDR begins the transmission. At the start of a
transmission, transmitter control logic automatically loads the transmit
shift register with a preamble of logic 1s. After the preamble shifts out,
the control logic transfers the SCDR data into the shift register. A logic 0
start bit automatically goes into the least significant bit position of the
shift register, and a logic 1 stop bit goes into the most significant bit
position.
When the data in the SCDR transfers to the transmit shift register, the
transmit data register empty (TDRE) flag in the SCI status register
(SCSR) becomes set. The TDRE flag indicates that the SCDR can
accept new data from the internal data bus.
Serial Communications Interface (SCI)
shows the structure of the SCI transmitter.
Serial Communications Interface (SCI)
General Release Specification
SCI Operation
65
Related parts for CM68HC05C4ACFB
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![MSD1819A-RT1](/images/no-image3.png)
Part Number:
Description:
NPN Silicon General Purpose Amplifier Transistor
Manufacturer:
Motorola / Freescale Semiconductor
![MSA1105](/images/no-image3.png)
Part Number:
Description:
Cascadable Silicon Bipolar MMIC Amplifier
Manufacturer:
Motorola / Freescale Semiconductor
![MMBR5031LT1](/images/no-image3.png)
Part Number:
Description:
NPN Silicon High-Frequency Transistor
Manufacturer:
Motorola / Freescale Semiconductor
![MMBR571](/images/no-image3.png)
Part Number:
Description:
NPN Silicon High Frequency Transisters
Manufacturer:
Motorola / Freescale Semiconductor
![MMBR5179LT1](/images/no-image3.png)
Part Number:
Description:
RF AMPLIFIER TRANSISTOR NPN SILICON
Manufacturer:
Motorola / Freescale Semiconductor
![MMBR521LT1](/images/no-image3.png)
Part Number:
Description:
HIGH-FREQUENCY TRANSISTOR PNP SILICON
Manufacturer:
Motorola / Freescale Semiconductor
![MMBR901LT1](/images/no-image3.png)
Part Number:
Description:
IC = 30 mA SURFACE MOUNTED HIGH-FREQUENCY TRANSISTOR NPN SILICON
Manufacturer:
Motorola / Freescale Semiconductor
![MMBR911LT1](/images/no-image3.png)
Part Number:
Description:
Silicon NPN Transistor
Manufacturer:
Motorola / Freescale Semiconductor
![MMBR941LT1](/images/no-image3.png)
Part Number:
Description:
NPN Silicon Low Noise, High-Frequency Transistors
Manufacturer:
Motorola / Freescale Semiconductor
![MMBR951LT1](/images/no-image3.png)
Part Number:
Description:
NPN Silicon Low Noise, High-Frequency Transistor
Manufacturer:
Motorola / Freescale Semiconductor
![2N6053](/images/no-image3.png)
Part Number:
Description:
Darlington Complementary Silicon Power Transistor - Pol=PNP / Pkg=TO3 / Vceo=60 / Ic=8 / Hfe=750-18k / fT(Hz)=4M / Pwr(W)=100
Manufacturer:
Motorola / Freescale Semiconductor
Datasheet:
![2N6116](/images/no-image3.png)
Part Number:
Description:
Silicon programmable unijuction transistor.
Manufacturer:
Motorola / Freescale Semiconductor
![2N4852](/images/no-image3.png)
Part Number:
Description:
Silicon PN unijinction transistor.
Manufacturer:
Motorola / Freescale Semiconductor
![LM104H](/images/no-image3.png)
Part Number:
Description:
Negative Voltage Regulator
Manufacturer:
Motorola / Freescale Semiconductor
![LM108AJ-8](/images/no-image3.png)
Part Number:
Description:
Super Gain Operational Amplifier
Manufacturer:
Motorola / Freescale Semiconductor