RM0082
LS_Fast IrDA controller
Doc ID 018672 Rev 1
571/844
26
LS_Fast IrDA controller
26.1 Overview
Within its low speed connectivity subsystem, the device provides a fast IrDA Controller
modeled according to the standard of the infrared data association (IrDA).
It is a programmable infrared controller that acts as an interface between the on-chip AHB
bus and infrared transceiver. This controller is able to perform the modulation and the
demodulation of the infrared signals and the wrapping of the IrDA link access protocol
(IrLAP) frames.
Main features of the fast IrDA (FIrDA) Controller are:
●
supports different standards:
–
IrDA serial infrared physical layer specification (IrPHY), version 1.3
–
IrDA link access protocol (IrLAP), version 1.1
●
supports different infrared modes and baud rates:
–
Serial infrared (SIR), with rates 9.6 Kbps, 19.2 Kbps, 38.4 Kbps, 57.6 Kbps and
115.2 Kbps
–
Medium infrared (MIR), with rates 576 Kbps and 1.152 Mbps
–
Fast infrared (FIR), with rate 4 Mbps.
●
Provides a transceiver interface compliant to all IrDA transceivers with configurable
polarity of TX and RX signals.
●
Integrates half-duplex infrared frame transmission and reception.
●
Integrates 16 bit CRC algorithm for SIR and MIR, and 32 bit CRC algorithm for FIR.
●
Generates preamble, start and stop flag.
●
Uses the RZI (return-to-zero inverted) modulation/demodulation scheme for SIR and
MIR, and the 4PPM (4 pulse position modulation) modulation/demodulation scheme for
FIR.
●
Provides synchronization by means of a DPLL in FIR mode.
●
Implements a payload data transfer controllable by either CPU or DMA controller.
●
Presents two clock domains:
–
a dedicated clock (irda_clk signal) for an accurate signal generation (for example.
48 MHz),), (see for more details the Miscellaneous register PRPH_CLK_CFG[bit
6:5] in
Table 165: PRPH_CLK_CFG register bit assignments
and PLL
programming sequence.
–
an independent and variable clock for the bus interface (for example. 13 MHz).
26.2 Block
diagram
shows the dataflow block diagram of the FIrDA controller.