How-To Guide

Table Of Contents
R01UH0823EJ0110 Rev.1.10 Page 997 of 1852
Nov 30, 2020
RX23W Group 33. Serial Communications Interface (SCIg, SCIh)
Table 33.14 lists examples of N settings in the BRR register in normal asynchronous mode. Table 33.15 lists the
maximum bit rate settable for each operating frequency. Examples of BRR (N) settings in clock synchronous mode and
simple SPI mode are listed in
Table 33.18. Examples of BRR (N) settings in smart card interface mode are listed in
Table 33.20. Examples of BRR (N) settings in simple I
2
C mode are listed in Table 33.22. In smart card interface mode,
the number of base clock cycles S in a 1-bit data transfer time can be selected. For details, refer to
section 33.6.4,
Receive Data Sampling Timing and Reception Margin
. Table 33.16 and Table 33.19 list the maximum bit rates
with external clock input.
When either the SEMR.ABCS or BGDM bit is set to 1 in asynchronous mode, the bit rate becomes twice that listed in
Table 33.14. When both of those bits are set to 1, the bit rate becomes four times the listed value.
Table 33.12 Clock Source Settings
SMR.CKS[1:0] Bit Setting Clock Source n
0 0 PCLK 0
0 1 PCLK/4 1
1 0 PCLK/16 2
1 1 PCLK/64 3
Table 33.13 Base Clock Settings in Smart Card Interface Mode
SCMR.BCP2 Bit Setting SMR.BCP[1:0] Bit Setting Base Clock Cycles for 1-bit Period S
0 0 0 93 clock cycles 93
0 0 1 128 clock cycles 128
0 1 0 186 clock cycles 186
0 1 1 512 clock cycles 512
1 0 0 32 clock cycles 32
1 0 1 64 clock cycles 64
1 1 0 372 clock cycles 372
1 1 1 256 clock cycles 256