RL78/D1A User's Manual: Hardware - Renesas

Under development
Preliminary document
Specifications in this document are tentative and subject to change.
RL78/D1A CHAPTER 13 ASYNCHRONOUS SERIAL INTERFACE LIN-UART (UARTF)
Therefore, the maximum baud rate that can be received by the destination is as follows.
BRmax = (FLmin/11) 1 22k
= Brate
21k + 2
Similarly, obtaining the following maximum allowable transfer rate yields the following.
10
k + 2 21k 2
FLmax = 11 FL FL = FL
11
2 k 2 k
21k 2
FLmax = FL 11
20 k
Therefore, the minimum baud rate that can be received by the destination is as follows.
BRmin = (FLmax/11) 1 20k
= Brate
21k 2
Table 13-10 shows the allowable baud rate error for UARTn and the destination calculated from the above-described
equations for obtaining the minimum and maximum baud rate values.
Division Ratio (k)
Table 13-10. Maximum/Minimum Allowable Baud Rate Error
Maximum Allowable Baud Rate Error Minimum Allowable Baud Rate Error
BN = 9 BN = 11 BN = 12 BN = 9 BN = 11 BN = 12
4 +2.85% +2.32% +2.12% 3.03% 2.43% 2.22%
8 +4.34% +3.52% +3.22% 4.47% 3.61% 3.29%
20 +5.10% +4.14% +3.78% 5.18% 4.19% 3.82%
50 +5.68% +4.60% +4.20% 5.70% 4.61% 4.21%
100 +5.78% +4.68% +4.27% 5.79% 4.69% 4.28%
256 +5.83% +4.72% +4.31% 5.83% 4.72% 4.31%
512 +5.85% +4.74% +4.33% 5.86% 4.74% 4.33%
1024 +5.87% +4.75% +4.33% 5.87% 4.75% 4.33%
2048 +5.87% +4.75% +4.34% 5.87% 4.75% 4.34%
4095 +3.42% +4.75% +4.34% 3.59% 4.75% 4.34%
Remarks 1. The reception accuracy depends on the bit count in 1 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
accuracy.
2. BN: Number of bits from the start bit to the stop bit
K: Setting values of UFnCTL1.UFnBRS[11:0]
R01UH0317EJ0004 Rev. 0.04 781
Feb. 22, 2013