MCCIRM Freescale Semiconductor / Motorola, MCCIRM Datasheet - Page 60

• Manufacturer Part Number: MCCIRM
• Description: MCCIRM Multi-Channel Communications Interface Reference Manual
• Manufacturer: Freescale Semiconductor / Motorola

SCI Submodule
5.3 SCI Pins
5.4 Serial Formats
Reference Manual
60
Four unidirectional pins are associated with the SCI. When the receiver
or transmitter associated with a given pin is not enabled (for instance,
when the RE or TE bit in the associated SCCR1 register is not set), the
pin automatically reverts to its general-purpose I/O function.
summarizes SCI pin function.
Data can be transmitted and received in a number of formats. The
following terms concerning data format are used in this section:
Transmit data
Receive data
•
•
•
•
•
•
•
Freescale Semiconductor, Inc.
Pin Name
For More Information On This Product,
Bit time — The time required to transmit or receive one bit of data;
one cycle of the baud frequency
Start bit — One bit time of logic 0 that indicates the beginning of a
data frame. A start bit must begin with a 1-to-0 transition.
Stop bit — One bit time of logic 1 that indicates the end of a data
frame
Frame — A complete unit of serial information. The SCI can use
10- or 11-bit frames.
Data frame — A start bit, a specified number of data bits (one of
which may be used as an address mark or parity bit or an extra
stop bit) and a final stop bit
Idle frame — A frame that consists of all 1s. An idle frame has no
start bit.
Break frame — A frame that consists of all 0s. A break frame has
no stop bits.
Go to: www.freescale.com
SCI Submodule
Mnemonic
RXDA
RXDB
TXDA
TXDB
Table 5-2. SCI Pin Function
Serial data input to SCIA receiver
Serial data input to SCIB receiver
Serial data output from SCIA transmitter
Serial data output from SCIB transmitter
Multichannel Communication Interface — Rev. 1.0
SCI Function
Table 5-2
MOTOROLA