TMP86PM49UG Datasheet, PDF (159/262 Pages) Toshiba Semiconductor – 8 Bit Microcontroller

TMP86PM49UG
12.4 Transfer Rate
The baud rate of UART1 is set of UART1CR1<BRG>. The example of the baud rate are shown as follows.
Table 12-1 Transfer Rate (Example)
BRG
000
001
010
011
100
101
16 MHz
76800 [baud]
38400
19200
9600
4800
2400
Source Clock
8 MHz
38400 [baud]
19200
9600
4800
2400
1200
4 MHz
19200 [baud]
9600
4800
2400
1200
600
When TC3 is used as the UART1 transfer rate (when UART1CR1<BRG> = “110”), the transfer clock and transfer
rate are determined as follows:
Transfer clock [Hz] = TC3 source clock [Hz] / TTREG3 setting value
Transfer Rate [baud] = Transfer clock [Hz] / 16
12.5 Data Sampling Method
The UART1 receiver keeps sampling input using the clock selected by UART1CR1<BRG> until a start bit is
detected in RXD1 pin input. RT clock starts detecting “L” level of the RXD1 pin. Once a start bit is detected, the
start bit, data bits, stop bit(s), and parity bit are sampled at three times of RT7, RT8, and RT9 during one receiver
clock interval (RT clock). (RT0 is the position where the bit supposedly starts.) Bit is determined according to major-
ity rule (The data are the same twice or more out of three samplings).
RXD1 pin
RT clock
Internal receive data
RXD1 pin
RT clock
Internal receive data
Start bit
Bit 0
RT0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7 8 9 10 11
Start bit
(a) Without noise rejection circuit
Bit 0
Start bit
Bit 0
RT0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7 8 9 10 11
Start bit
(b) With noise rejection circuit
Bit 0
Figure 12-4 Data Sampling Method
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