CHAPTER 11 SERIAL INTERFACE FUNCTION
388
User’s Manual U14359EJ4V0UM
Therefore, the maximum baud rate that can be received at the transfer destination is as follows.
Brate
2
21k
k
22
(FLmin/11)
BRmax
1
+
=
=
−
Similarly, the maximum allowable transfer rate can be obtained as follows.
FL
k
2
2
k
21
FL
k
2
2
k
FL
11
FLmax
11
10
×
−
=
×
×
+
−
×
=
×
11
FL
k
20
2
k
21
FLmax
×
−
=
Therefore, the minimum baud rate that can be received at the transfer destination is as follows.
Brate
2
21k
k
20
(FLmax/11)
BRmin
1
−
=
=
−
The allowable baud rate error of UARTn and the transfer destination can be obtained as follows from the
expressions described above for computing the minimum and maximum baud rate values.
Table 11-4. Maximum and Minimum Allowable Baud Rate Error
Division Ratio (k)
Maximum Allowable
Baud Rate Error
Minimum Allowable
Baud Rate Error
8
+3.53%
−
3.61%
20
+4.26%
−
4.31%
50
+4.56%
−
4.58%
100
+4.66%
−
4.67%
255
+4.72%
−
4.73%
Remarks 1.
The reception precision depends on the number of bits in one frame, the input clock frequency,
and the division ratio (k). The higher the input clock frequency and the larger the division ratio
(k), the higher the precision.
2.
k: BRGCn setting value (n = 0 to 2)
