mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 647

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

16.9.13 DPLL and Serial Infrared Encoder/Decoder
IrDA is a family of specifications intended to facilitate the interconnection of computers and
peripherals using a directed half-duplex serial infrared physical communications medium.
The infrared data association (IrDA) physical layer standard version 1.1 specifies three
modes of operation, each one with a distinct modulation scheme and signaling rate.
Figure 16-71 illustrates how to implement a general infrared link with the MPC823 using an
SCC, IrDA encoder/decoder module, and external IrDA transducer module.
The IrDA DPLL is driven by one of the baud rate generator outputs or by an external clock
called a high-speed receive/transmit clock (HSRCLK/HSTCLK) that is used as a reference
clock for the IrDA DPLL. In low- and middle-speed modes, the HSRCLK and HSTCLK
frequency must be 16x the serial frequency. In high-speed mode, the ratio between the
HSRCLK/HSTCLK frequency and the serial frequency depends on the IrDA DPLL mode,
which is currently 12x the serial frequency. Therefore, for high-speed mode IrDA operation
from an external clock, a 48MHz frequency must be provided. It you are using a source for
HSRCLK and HSTCLK, the minimum system frequency must be 48MHz. See
Section 16.9.20.5 Programming Model for more information.
• Low speed mode—2.4Kb/s to 115.2Kb/s
• Middle speed mode—0.576 Mb/s or 1.152 Mb/s
• High speed mode—4 Mb/s
MPC823
SCCx
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 16-71. Serial IrDA Link
MPC823 REFERENCE MANUAL
TXDx
RXDx
Go to: www.freescale.com
IR TRANSMIT
IR RECEIVE
ENCODER/
ENCODER
DECODER
DECODER
MODULE
TRANSDUCER
DRIVER&LED
& RECEIVER
DETECTOR
MODULE
OUTPUT
Communication Processor Module
IR
IR OUT
IR IN
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