S1
S2
T
A4
A3
A2
A1
A0
C5
C4
C3
C2
C1
C0
uart-018
S
C0
C1
C2
C3
C4
C5
C6
D0
D1
D2
D3
D4
uart-019
Start-bit
0
1
T
2.4 ms
1.2 ms
1.8 ms
Complete frame
(45 ms)
Frame space
(variable)
uart-020
Preliminary
www.ti.com
Architecture
Figure 19-13. RC-5 Standard Packet Format
Where:
S1, S2:
Start bits (always 1)
T:
Toggle bit
A4..A0:
Address (or system) bits
C5..C0:
Command bits
The toggle bit T changes each time a new command is transmitted to allow detection of pressing the
same key twice (or effectively receiving the same data from the host consecutively). Since a code is
being sent as long as the CPU transmits characters to the UART for transmission, a brief delay in the
transmission of the same command would be detected by the use of the toggle bit. The address bits
define the machine or device that the Infrared transmission is intended for and the command defines
the operation.
To accommodate an extended RC-5 format, the S2 bit is replaced by an additional command bit (C6)
that allows the command range to increase to 7 bits. This format is known as the extended RC-5
format.
The SIRC encoding uses the duration of modulation for mark and space; hence the duration of data bits
inside the standard frame length will vary depending upon the logic 1 content.
shows the
packet format and bit encoding. As
shows, 1 start bit of 2 ms and control codes are
followed by data that constitute the entire frame.
Figure 19-14. SIRC Packet Format
NOTE:
The encoding must take a standard duration, but the contents of the data can vary. This
implies that the control software for emitting and receiving data packets must exercise a
scheme of interpacket delay, where the emission of successive packets can be done only
after a real-time delay has expired.
Figure 19-15. SIRC Bit Transmission Example
This document does not describe all encoding methods and techniques; the preceding information
shows the considerations required to employ different encoding methods for different industry-standard
protocols. See industry-standard documentation for specific methods of encoding and protocol usage.
1697
SPRUGX9 – 15 April 2011
UART/IrDA/CIR Module
© 2011, Texas Instruments Incorporated
Содержание TMS320C6A816 Series
Страница 2: ...Preliminary 2 SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 92: ...92 Read This First SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1122: ...1122 Multichannel Audio Serial Port McASP SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1562: ...1562 Real Time Clock RTC SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1658: ...1658 Timers SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1750: ...1750 UART IrDA CIR Module SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1984: ...1984 Universal Serial Bus USB SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...