IrDA Support
12-36
ADSP-BF535 Blackfin Processor Hardware Reference
layer known as IrDA SIR (9.6/115.2 Kbps rate) is based on
return-to-zero-inverted (RZI) modulation. Pulse position modulation is
not supported.
Using the 16x date rate clock, RZI modulation is achieved by inverting
and modulating the non-return-to-zero (NRZ) code normally transmitted
by the UART. On the receive side, the 16x clock is used to determine an
IrDA pulse sample window, from which the RZI-modulated NRZ code is
recovered. The minimum pulse duration, that is, the time required for
valid 0 receive data to be detected, is programmable.
IrDA support is enabled by setting the
IREN
bit in the UART0 Infrared
Control register. The IrDA application requires external transceivers.
UART0 Infrared Control Register (UART0_IRCR)
The
UART0_IRCR
register, shown in
Figure 12-28
, contains bits that con-
trol all IrDA related features. These include the enable bit for IrDA mode
of operation, bits to specify the minimum receive pulse width, and a bit to
specify the polarity of the data received.
Figure 12-28. UART0 Infrared Control Register
0
0
0
0
15 14
13 12
11 10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
UART0 Infrared Control Register (UART0_IRCR)
IREN (Enable IrDA Mode)
1 - Enable IrDA
0 - Disable IrDA
Reset 0x0000
UART0 Infrared Control Register (UART0_IRCR)
0xFFC0 1810
IRPD[9:0] (IrDA Receive
Pulse Duration)
Minimum number of Serial
In samples required for a
valid pulse to be detected.
IRPD=
((Pulse width(sec)
xSCLK freq)–2).
IRPOL (IrDA Receive
Polarity)
0 - Serial In Idle low
Data 0 = positive pulse
Data 1 = no pulse
1 - Serial In Idle high
Data 0 = negative pulse
Data 1 = no pulse
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...