TC35679FSG-002

2018-01-17

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4.3.7.

Error Detecting Functions

TC35679 UART interface has 3 kinds of error detecting functions.



Receiver timeout error



Receiver over run error



Receiver frame error

Receiver timeout error detection judges an error if an UART RX message made from several RX frames has an RX frame interval

longer than a certain value. The interval is counted by internal timer. Keep the interval between RX frames less than 12 time frames

that belong to an RX message. For UART1, keep intervals between different RX messages more than 12 time frames. For

example, 115200 bps has 0.087 ms for 1 frame, the interval between RX messages should be longer than 0.087 ms × 12 = 1.04

ms. RX messages that has intervals less than 12 time frames gives an error because TC35679 sees them as one UART RX

message. Interval of the received frame is the default in the 12 time frame, but it can be changed by the command.

In the case of UART2, of different UART receive message interval is more than 14 ms.

Figure 4-9 RX frames and RX messages

Receiver over run error judges if UART receive frame buffer internal TC35679 is overflowed. Normally, this overflow does not

happen when the flow control mentioned in 4.2.4 is activated for data communication.

Receiver frame error judges if failing recognize the unit frame. A frame formation is judged as failure when its start bit is detected

and the corresponding stop bit is detected as “0”.

UART RX data

UART RX message

UART RX message

< 12 time frames

< 12 time frames

< 12 time frames

> 12 time frames

1 time frame