
CHAPTER 15 SERIAL INTERFACE UART2
303
User
’
s Manual U14260EJ3V1UD
15.4.4 Infrared data transfer (IrDA) mode
In this mode, pulses can be output, transmitted, or received in the data format of the IrDA specifications. This
mode can be used to transmit or receive data to or from a digital device such as a personal computer.
(1) Registers to be used
Asynchronous serial interface mode register 2 (ASIM2)
Asynchronous serial interface status register 2 (ASIS2)
Baud rate generator control register 2 (BRGC2)
Asynchronous serial interface transmit status register 2 (ASIF2)
Clock select register 2 (CKSEL2)
Transfer mode specification register 2 (TRMC2)
Port mode register 3 (PM3)
Port register 3 (P3)
The relationship between the register settings and pins is shown below.
Table 15-11. Relationship Between Register Settings and Pins (Infrared Data Transfer (IrDA) Mode)
ASIM2
TRMC2
PM34
P34
PM35
P35
Operation Pin Function
POW TXE2 RXE2 PS21 PS20
ER2
CL2
SL2
I
SEM2 TRM12 TRM02 ISMD2
MPIEN2
MPS2
Mode
P34/
SI3/
TxD2
P35/
SO3/
RxD2
1
0
1
0/1
0/1
0/1
×
0/1
1
×
×
×
×
×
Note
×
Note
1
×
Reception P34
RxD2
1
1
0
0/1
0/1
0/1
0/1
×
1
×
0/1
×
×
0
0
×
Note
×
Note
Transmission
TxD2
P35
1
1
1
0/1
0/1
0/1
0/1
0/1
1
×
0/1
×
×
0
0
1
×
Transmission/
TxD2
reception
RxD2
Note
Can be set as port function.
Cautions 1.
When using UART2, stop the operation of SIO3 (bit 7 (CSIE3) of serial operation mode register
3 (CSIM3) = 0).
To transfer data in the infrared data transfer (IrDA) mode, the following conditional expression
must be satisfied for the transmit pulse width.
(Conditional expression)
1.41
μ
s
≤
Transmit pulse width (set values of TPW20 to TPW23) < Transfer rate (set values of
MDL20 to MDL27)
2.
Remark
×
: don
’
t care, ASIM2: Asynchronous serial interface mode register 2,
TRMC2: Transfer mode specification register 2, PM
××
: Port mode register,
P
××
: Port output latch, TPW20 to TPW23: Bits 0 to 3 of clock select register 2 (CKSEL2),
MDL20 to MDL27: Bits 0 to 7 of baud rate generator control register 2 (BRGC2)