
18 UART
18-18
EPSON
S1C17003 TECHNICAL MANUAL
0x4103/0x4123: UART Ch.x Mode Registers (UART_MODx)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
UART Ch.x
Mode Register
(UART_MODx)
0x4103
0x4123
(8 bits)
D7–5
–
reserved
–
0 when being read.
D4
CHLN
Character length
1 8 bits
0 7 bits
0
R/W
D3
PREN
Parity enable
1 With parity
0 No parity
0
R/W
D2
PMD
Parity mode select
1 Odd
0 Even
0
R/W
D1
STPB
Stop bit select
1 2 bits
0 1 bit
0
R/W
D0
SSCK
Input clock select
1 External
0 Internal
0
R/W
The “x” in register names indicates the channel number (0 or 1).
0x4103: UART Ch.0 Mode Register (UART_MOD0)
0x4123: UART Ch.1 Mode Register (UART_MOD1)
D[7:5]
Reserved
D4
CHLN: Character Length Select Bit
Selects the serial transfer data length.
1 (R/W): 8 bits
0 (R/W): 7 bits (default)
D3
PREN: Parity Enable Bit
Enables the parity function.
1 (R/W): With parity
0 (R/W): No parity (default)
PREN is used to select receive data parity checking and to determine whether a parity bit is added to
transmitted data. Setting PREN to 1 parity-checks the received data. A parity bit is automatically added
to the transmitted data. If PREN is set to 0, no parity bit is checked or added.
D2
PMD: Parity Mode Select Bit
Selects the parity mode.
1 (R/W): Odd parity
0 (R/W): Even parity (default)
Writing 1 to PMD selects odd parity; writing 0 to it selects even parity. Parity checking and parity bit
addition are enabled only when PREN (D3) is set to 1. The PMD setting is disabled if PREN (D3) is 0.
D1
STPB: Stop Bit Select Bit
Selects the stop bit length.
1 (R/W): 2 bits
0 (R/W): 1 bit (default)
Writing 1 to STPB selects two stop bits; writing 0 to it selects one bit. The start bit is fixed at one bit.
D0
SSCK: Input Clock Select Bit
Selects the input clock.
1 (R/W): External clock (SCLKx)
0 (R/W): Internal clock (default)
Selects whether the internal clock (8-bit timer output clock) or external clock (input via SCLKx pin) is
used. Writing 1 to SSCK selects the external clock; Writing 0 to it selects the internal clock.