R01UH0823EJ0100 Rev.1.00
Page 973 of 1823
Jul 31, 2019
RX23W Group
33. Serial Communications Interface (SCIg, SCIh)
33.2.7
Serial Mode Register (SMR)
Note:
Some bits in SMR have different functions in smart card interface mode and non-smart card interface mode.
(1) Non-Smart Card Interface Mode (SCMR.SMIF = 0)
Note 1. n is the decimal notation of the value of n in the BRR register (refer to section 33.2.11, Bit Rate Register (BRR)).
Note 2. In other than asynchronous mode, this bit setting is invalid and a fixed data length of 8 bits is used.
Note 3. LSB first is fixed and the MSB (bit 7) in the TDR register is not transmitted in transmission.
Note 4. Writable only when TE in SCR = 0 and RE in SCR = 0 (both serial transmission and reception are disabled).
CKS[1:0] Bits (Clock Select)
These bits select the clock source for the on-chip baud rate generator.
For the relation between the settings of these bits and the baud rate, refer to
section 33.2.11, Bit Rate Register (BRR)
Disables/enables the multi-processor communications function. The settings of the PE bit and PM bit are invalid in
multi-processor mode.
Address(es): SCI1.SMR 0008 A020h, SCI5.SMR 0008 A0A0h, SCI8.SMR 0008 A100h, SCI12.SMR 0008 B300h
b7
b6
b5
b4
b3
b2
b1
b0
CM
CHR
PE
PM
STOP
MP
CKS[1:0]
Value after reset:
0
0
0
0
0
0
0
0
Bit
Symbol
Bit Name
Description
R/W
b1, b0
Clock Select
b1 b0
0 0: PCLK (n = 0)*
1 1: PCLK/64 (n = 3)*
b2
Multi-Processor Mode
(Valid only in asynchronous mode)
0: Multi-processor communications function is disabled
1: Multi-processor communications function is enabled
b3
Stop Bit Length
(Valid only in asynchronous mode)
0: 1 stop bit
1: 2 stop bits
b4
Parity Mode
(Valid only when the PE bit is 1)
0: Selects even parity
1: Selects odd parity
b5
Parity Enable
(Valid only in asynchronous mode)
When transmitting
0: Parity bit addition is not performed
1: The parity bit is added
When receiving
0: Parity bit checking is not performed
1: The parity bit is checked
b6
Character Length
(Valid only in asynchronous mode*
Selects in combination with the SCMR.CHR1 bit.
CHR1
CHR
0
0: Transmit/receive in 9-bit data length
0
1: Transmit/receive in 9-bit data length
1
0: Transmit/receive in 8-bit data length (initial value)
1
1: Transmit/receive in 7-bit data length*
b7
Communications Mode
0: Asynchronous mode or simple I
2
C mode
1: Clock synchronous mode or simple SPI mode