Technical information

APPLICATION
2.3 Serial I/O
2-47
3800 GROUP USER’S MANUAL
Control procedure : Figure 2.3.33 shows a control procedure at a transmitting side, and Figure 2.3.34
shows a control procedure at a receiving side.
RESET
End of communication
(Address : 1A 16 )
(Address : 1B
16 )
(Address : 1C
16 )
(Address : 08
16 ), bit0
(Address : 09
16 )
P4 (Address : 0816), bit0
1
Y
N
TB/RB (( Address : 18 16 )
The second byte of
a transmission data
SIOSTS (Address : 19
16), bit0?
1
0
SIOSTS (Address : 1916), bit2?
1
0
Initialization
SIOCON
UARTCON
BRG
P4
P4D
8–1
....
TB/RB ( Address : 18 16 )
The first byte of a
transmission data
P4 (Address : 08
16), bit0 0
1
0
X : This bit is not used in this application.
Set it to “0” or “1.” It’s value can be disregarded.
Set port P40 for a communication control.
An interval of 10 ms is generated by a timer.
Start of communication.
Write a transmission data
The Transmit buffer empty flag is set to “0”
by this writing.
Write a transmission data
The Transmit buffer empty flag is set to “0”
by this writing.
Check to be transferred data from the Transmit
buffer register to the Transmit shift register.
(Transmit buffer empty flag)
Check to be transferred data from the Transmit
buffer register to the Transmit shift register.
(Transmit buffer empty flag)
Check a shift completion of the Transmit shift register.
(Transmit shift register shift completion flag)
SIOSTS (Address : 19
16), bit0?
0
XXXXXXX1
2
●
●
●
●
●
●
●
●
●
●
Pass 10 ms?
1001X001
2
000010002
Fig. 2.3.33 Control procedure at a transmitting side [Communication using UART]