M38002M4 Datasheet, PDF (85/173 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Serial I/O
Figure 2.3.21 shows a setting of serial I/O related registers, and Figure 2.3.22 shows a setting of serial
I/O transmission data.
SIOCON
Serial I/O control register (Address : 1A16)
b7
b0
1101 1000
BRG count source selection bit : f(XIN)
Serial I/O synchronous clock selection bit : BRG/4
SRDY output enable bit : Not use the SRDY signal output function
Transmit interrupt source selection bit : Transmit shift operating completion
Transmit enable bit : Transmit enabled
Receive enable bit : Receive disabled
Serial I/O mode selection bit : Clock synchronous serial I/O
Serial I/O enable bit : Serial I/O enabled
UART control register (Address : 1B16)
b7
b0
UARTCON
0
BRG
ICON1
P45/TXD P-channel output disable bit : CMOS output
Baud rate generator (Address : 1C16)
b7
b0
7
Set “division ratio – 1”
Interrupt control register 1 (Address : 3E16)
b7
b0
0
IREQ1
Serial I/O transmit interrupt enable bit : Interrupt disabled
Interrupt request register 1 (Address : 3C16)
b7
b0
0
Serial I/O transmit interrupt request bit
Using this bit, check the completion of
transmitting 1-byte base data.
“1” : Transmit shift completion
Fig. 2.3.21 Setting of serial I/O related registers [Output of serial data]
TB/RB
Transmit/Receive buffer register (Address : 18 16)
b7
b0
Set a transmission data.
Check that transmission of the previous data is
completed before writing data (bit 3 of the
Interrupt request register 1 is set to “1”).
Fig. 2.3.22 Setting of serial I/O transmission data [Output of serial data]
3800 GROUP USER’S MANUAL
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