M38203M4 Datasheet, PDF (213/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.5 Serial I/O1
(4) UART control register (UARTCON)
This register (address 001B16) controls the transfer data format in the UART mode and the output
format of the P45/TxD pin.
UART control register
b7 b6 b5 b4 b3 b2 b1 b0
UART control register (UARTCON) [Address 1B16]
B
Name
Functions
0 Character length
0: 8 bits
selection bit (CHAS) 1: 7 bits
1 Parity enable bit
(PARE)
0: Parity checking disabled
1: Parity checking enabled
2 Parity selection bit
(PARS)
0: Even parity
1: Odd parity
3 _{Stop bit length}
0: 1 stop bit
selection bit (STPS) 1: 2 stop bits
4 P45/TxD P-channel
output disable bit
(POFF)
0: CMOS output (in output mode)
1: N-channel open-drain output
(in output mode)
5 Nothing is allocated. These bits cannot be written
to to and are fixed to “1” at reading.
7
At reset R W
0
0
0
0
0
1 1^×
Fig. 2.5.17 Structure of UART control register
sCharacter length selection bit (bit 0)
This bit selects data bit length of the UART transfer data format.
In the “0” state, the data bit length is 8 bits. In the “1” state, the data bit length is 7 bits.
sParity enable bit (bit 1)
This bit is set to “1” to make a parity check and to “0” to make no parity check.
In the “1” state, the parity error flag becomes valid.
sParity selection bit (bit 2)
This bit selects a parity type of the UART transfer data format.
In the “0” state, the parity type is an even parity. In the “1” state, it is an odd parity.
sStop bit length selection bit (bit 3)
This bit selects a stop bit length of the UART transfer data format.
In the “0” state, the stop bit length is 1 stop bit.
In the “1” state, the stop bit length is 2 stop bits.
sP45/TxD P-channel output disable bit (bit 4)
This bit controls the output type of the P45/TxD pin.
In the “0” state, the output type is CMOS output in the output mode. In the “1” state, the output type
is N-channel open-drain output in the output mode.
The 5 low-order bits of the UART control register can be read and written. The 3 high-order bits are
unused and read-only bits. At reading, all the bits are set to “1.”
3820 GROUP USER’S MANUAL
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