mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 754

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

Freescale Semiconductor, Inc.
Communication Processor Module
The receiver synchronizes on the synchronization pattern that is located in the DSR. For
instance, if 4-BIT SYNC is selected, reception begins as soon as these four bits are
received, beginning with the first bit following the 4-BIT SYNC field. The transmitter
synchronizes on the receiver pattern if the RSYN bit of the GSMR_H is set. This effectively
links the transmitter synchronization to the receiver synchronization.
16.9.21.4.2 External Synchronization Signals. If the SYNL field of the GSMR_H is
programmed to 00, an external signal is used to begin the sequence. The CTSx pin is used
for the transmitter and the CDx pin is used for the receiver and these pins share two
options— pulse and sampling.
The pulse option determines whether the CDx or CTSx pins only need to be asserted once
to begin reception/transmission or whether they must be asserted and stay that way for the
duration of the transparent frame. In the GSMR_H, the CDP and CTSP bits control the pulse
options. If you expect a continuous stream of data without interruption, then you must use
the pulse operation. However, if you are trying to identify frames of transparent data, then
you must use the envelope mode of these pins.
The sampling option determines the delay between the CDx and CTSx signals that is
asserted and the reaction of a serial communication controller. You can assume that these
pins are asynchronous to the data and internally synchronized by a serial communication
controller or you can assume that they are synchronous to the data for faster operation. The
CDS and CTCC bits of the GSMR_H control the sampling option. You can also link the
transmitter synchronization to the receiver synchronization. The pulse/envelope and
sampling options are described in Section 16.9.10 Controlling SCCx Timing.
MPC823 REFERENCE MANUAL
MOTOROLA
For More Information On This Product,
Go to: www.freescale.com