
100
2. APPLICAT ION
MITSUBISHI MICROCOMPUTER
3819 Group
2.3 Serial I/O
3819 Group USER’S MANUAL
Control procedure :
In this example, a serial communication is performed at the beginning of the main routine
which loops in a certain cycle.
Fig. 2.3.22 Control procedure [Data transmission or reception using automatic transfer]
Initialize the serial I/O 1
Set the related functions for using automatic
transfer.
Generate the timing of a certain cycle by
using the timer or other functions.
Control so that the main routine is executed
in a certain cycle.
Set one block (8 byte) of transmission data
in the RAM.
Set the data pointer (set “8 byte – 1”).
Start the automatic transfer.
It is possible to execute the other process-
ing during an automatic transfer.
(a part of the main processing is executed.)
Check the completion of an automatic
transfer.
Transfer a data stored to the Serial I/O
automatic transfer RAM to RAM for
processing of reception data.
Perform the following processing in the main
processing.
1. The processing of the data transferred into
the RAM for processing of reception data.
2. The preparation of the next transmission
data.
RESET
Initialization
SIO1CON
SIOAC
SIOAI
SIODP
I.
(Address:19
16
)
(Address:1A
16
)
(Address:1C
16
)
(Address:18
16
)
(Address:3E
16
), bit3
01001010
2
00000001
2
30
8 – 1
0
SIODP (Address:18
16
) 7
SIOAC (Address:1A
16
), bit 1 1
1
SIOAC (Address:1A
16
), bit1
0
N
Has the time specified for the cycle
control of a main routine elapsed
Y
Serial I/O automatic transfer RAM
(Address:0F00
16
to 0F07
16
)
a transmission
data
Serial I/O automatic
transfer RAM
(Address:0F00
16
to 0F07
16
)
RAM for processing
of a reception data
Main processing
G
G
G
G
G
G
G
G
G
G
G