mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 617

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

TTX—Transparent Transmitter
The serial communication controllers offer totally transparent operation. However, to
increase flexibility, totally transparent operation is not configured with the MODE field of the
GSMR_L, but with the TTX and TRX bits. This allows you to implement unique applications,
such as configuring an SCCx receiver for HDLC operation and configuring a transmitter for
totally transparent operation. This can be done by setting the MODE field to HDLC, TTX to
1 and TRX to 0.
CDP—Carrier-Detect Pulse
This bit must be set if a serial communication controller is used in the time-slot assigner.
CTSP—CTS Pulse
CDS—Carrier-Detect Sampling
0 = Normal operation.
1 = The transmitter operates in totally transparent mode, regardless of the protocol
0 = Normal operation (envelope mode). The CDx signal must envelope the frame.
1 = Pulse mode. Once the CDx signal is asserted, synchronization has been achieved
0 = Normal operation (envelope mode). The CTSx signal must envelope the frame.
1 = Pulse mode. Once the CTSx signal is asserted, synchronization has been
0 = The CDx signal is assumed to be asynchronous with the data. It is internally
1 = The CDx signal is assumed to be synchronous with the data, which speeds up
selected for the receiver in the MODE field of the GSMR_L.
Negating CDx while receiving data causes a CDx lost error.
and further transitions of CDx have no effect on reception.
Negating CTSx while transmitting data causes a CTSx lost error.
achieved and further transitions of CTSx have no effect on transmission.
synchronized by a serial communication controller and then data is received.
operation. In this mode, CDx must transition while the receive clock is in the low
state. As soon as CDx is low, data is received. This mode is especially useful when
connecting an MPC823 in transparent mode because it allows the RTSx signal of
one MPC823 to be directly connected to the CDx signal of another MPC823.
Note: Full-duplex transparent operation for a serial communication controller is
obtained by setting the TTX and TRX bits. The serial communication controllers
cannot operate with Ethernet on the receiver or while transparent operation is on
the transmitter. In other words, if the MODE field is set to Ethernet, then TTX
must equal TRX or erratic operation will occur.
Freescale Semiconductor, Inc.
For More Information On This Product,
MPC823 REFERENCE MANUAL
Go to: www.freescale.com
Communication Processor Module
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