IRCC SMSC Corporation, IRCC Datasheet - Page 61

• Manufacturer Part Number: IRCC
• Description: INFRARED COMMUNICATIONS CONTROLLER
• Manufacturer: SMSC Corporation

The IrDA FIR pulse and signaling violations listed
in this section are considered framing errors.
When the Frame Error bit in the IrCC Line Status
register is one, a framing error has occurred.
The IrDA receiver response to framing errors
depends upon when the errors occur. Framing
errors that occur before a valid BOF has been
detected will always set the Frame Error bit but
will not alter the system state in any other way;
i.e., the abort bit is not activated.
errors occur following a valid BOF, i.e. while
nActive Frame is zero, the message is aborted.
For both the HDLC and 4PPM encoding
schemes, messages with data fields larger than
the value contained in the data size register
violate IrDA framing rules but are not aborted.
NOTE: the Size Error and the Frame Error bits
are set. Pulses less than 60ns should be ignored,
in all modes. The events listed in the following
two sections are framing errors.
1.152Mbps
Pulse Widths greater than one bit-cell. Invalid
BOF: includes data fields before BOF, pulse-
width violations during BOF, and subsequent
invalid BOFs (including Aborts) following a valid
BOF before the Address field. Invalid data fields:
includes frames with invalid data field characters
(including aborts), and pulse-width violations
during a data field (including during CRC).
Invalid EOF fields: includes invalid EOF flags
(including Aborts), pulse-width violations, and
subsequent invalid EOFs following a valid EOF.
4Mbps
Pulse Widths greater than two chip times. Invalid
PA field: includes invalid PA symbols, pulse-
width violations, and subsequent invalid PA
If framing
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(including Aborts) before the STA field. Invalid
STA field: includes invalid STA symbols, pulse-
width violations, and subsequent invalid STA
symbols following at least one valid symbol
(including Aborts) before the payload data.
Invalid Data field: includes frames with invalid
data symbols (including Aborts), and pulse-width
violations during a data field (including during
CRC). Invalid EOF field: includes invalid EOF
flag (including Aborts), pulse-width violations,
and subsequent invalid EOFs following a valid
EOF.
CONSUMER IR ENCODER TIMING
The Consumer IR-mode SCE does not require
the framing signals that are specified in the IrDA-
mode timing, although both modes utilize the
nActive Frame and EOM Interrupt. There is also
no need to differentiate the IrDA-mode EOM
signal from an inactive nActive Frame.
Consumer IR-mode SCE operates at the bit
rates set in the Consumer IR Bit Rate Register.
The Consumer IR-mode SCE can operate in
Programmed I/O or DMA mode.
Generator is not used.
Transmit Timing
The SCE TV Remote transmitter uses the same
enabling
transmitter (see page 57). Note: the IrDA-mode
Active SIP Pulse Tx Enable timing restriction
does not apply. Once enabled, the TV Remote
transmitter operates until the FIFO underruns
(Figure 30).
Interrupt signals behave as shown.
Modes bits are reset to zero, disabling the
transmitter, following nActive Frame.
mechanisms
The nActive Frame and EOM
as
the
IrDA-mode
The CRC
The SCE
The