M38002M4 Datasheet, PDF (93/173 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Serial I/O
Transmitting side
Serial I/O status register (Address : 1916)
b7
b0
SIOSTS
Transmit buffer empty flag
• Check to be transferred data from the Transmit buffer
register to the Transmit shift register.
• Writable the next transmission data to the Transmit buffer
register at being set to “1.”
Transmit shift register shift completion flag
Check a completion of transmitting 1-byte data with this flag.
“1” : Transmit shift completed
Serial I/O control register (Address : 1A16)
b7
b0
SIOCON ^{1 0 0 1 0 0 1}
BRG count source selection bit : f(XIN)/4
Serial I/O synchronous clock selection bit : BRG/16
SRDY output enable bit : Not use SRDY out
Transmit enable bit : Transmit enabled
Receive enable bit : Receive disabled
Serial I/O mode selection bit : Asynchronous serial I/O(UART)
Serial I/O enable bit : Serial I/O enabled
UART control register (Address : 1B16)
b7
b0
UARTCON
01 00
Character length selection bit : 8 bits
Parity enable bit : Parity checking disabled
Stop bit length selection bit : 2 stop bits
P45/TXD P-channel output disable bit : CMOS output
Baud rate generator (Address : 1C16)
b7
b0
f(XIN)
BRG
7
Set
Transfer bit rate ! 16
!
–1
m^T
T when bit 0 of the Serial I/O control register (Address : 1A16) is set to “0,”
a value of m is 1.
when bit 0 of the Serial I/O control register (Address : 1A16) is set to “1,”
a value of m is 4.
Fig. 2.3.31 Setting of related registers at a transmitting side [Communication using UART]
3800 GROUP USER’S MANUAL
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