13 UART (UART3)
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
13-13
(Rev. 2.00)
Bit 0
STPB
This bit sets the stop bit length.
1 (R/W): 2 bits
0 (R/W): 1 bit
Notes: • The UART3_nMOD register settings can be altered only when the UART3_nCTL.MODEN bit
= 0.
• Do not set both the UART3_nMOD.IRMD and UART3_nMOD.CAREN bits simultaneously.
UART3 Ch.
n
Baud–Rate Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
UART3_nBR
15–12 –
0x0
–
R
–
11–8 FMD[3:0]
0x0
H0
R/W
7–0 BRT[7:0]
0x00
H0
R/W
Bits 15–12 Reserved
Bits 11–8 FMD[3:0]
Bits 7–0
BRT[7:0]
These bits set the UART3 transfer rate. For more information, refer to “Baud Rate Generator.”
Notes: • The UART3_nBR register settings can be altered only when the UART3_nCTL.MODEN bit = 0.
• Do not set the UART3_nBR.FMD[3:0] bits to a value other than 0 to 3 when the UART3_
nMOD.BRDIV bit = 1.
UART3 Ch.
n
Control Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
UART3_nCTL
15–8 –
0x00
–
R
–
7–2 –
0x00
–
R
1
SFTRST
0
H0
R/W
0
MODEN
0
H0
R/W
Bits 15–2 Reserved
Bit 1
SFTRST
This bit issues software reset to the UART3.
1 (W):
Issue software reset
0 (W):
Ineffective
1 (R):
Software reset is executing.
0 (R):
Software reset has finished. (During normal operation)
Setting this bit resets the UART3 transmit/receive control circuit and interrupt flags. This bit is auto-
matically cleared after the reset processing has finished.
Bit 0
MODEN
This bit enables the UART3 operations.
1 (R/W): Enable UART3 operations (The operating clock is supplied.)
0 (R/W): Disable UART3 operations (The operating clock is stopped.)
Note
: If the
UART3_nCTL.MODEN bit is altered from 1 to 0 while sending/receiving data, the data
being sent/received cannot be guaranteed. When setting the UART3_nCTL.MODEN bit to 1
again after that, be sure to write 1 to the UART3_nCTL.SFTRST bit as well.