IRCC2.0 SMSC Corporation, IRCC2.0 Datasheet - Page 22

• Manufacturer Part Number: IRCC2.0
• Description: Infrared Communications Controller
• Manufacturer: SMSC Corporation

4PPM BOF Counting
The IrCC 2.0 can account for system-dependent
limitations such as long interrupt latencies and
transceiver stabilization times by increasing the
number of PA flags at the beginning of every
4PPM frame (Figure 16).
4PPM Back-to-Back Frame Transmission
Back-to-back, or brick walled frames are allowed
with 32 or more PA flag bytes between the STO
field of the first frame and the STA field of the
PA (#1)
Previous
Frame
STO
...
Sequence
Appends 0 - 4095 PA Bytes
16-byte
to Beginning of Frame
PA (#16)
BOF COUNT register
FIGURE 17 - BRICK WALLED 4 MBPS FRAMES
PA
between Brick Walled Frames
Inserts 0 - 4095 PA Bytes
FIGURE 16 - 4PPM EXTENDED BOF
Sequence
BW COUNT register
16-byte
PA
8-bit Start
Field
STA
STA
8-bit Address
22
ADDR
Field
The BOF COUNT register contains the number
of additional PA bytes that are to be appended to
the standard 4PPM BOF characters. Note: The
BOF COUNT extensions only apply to messages
that start from an idle line state; i.e., BOF
counting
messages.
second frame. Additional flags can be added by
programming the Brick Wall Count register.
Note: The BOF COUNT extensions do not apply
to brick walled messages.
Brick Walled Frame
8-bit Address
ADDR
Field
8-bit Control field plus up to 2K - 3 bytes
does
2K - 3 bytes Information Field
Information Field
8-bit Control field plus up to
not
DATA
apply
DATA
to
brick
walled