CHAPTER 14 SERIAL INTERFACE UART6
User’s Manual U16899EJ2V0UD
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(g) Noise filter of receive data
The RxD6 signal is sampled with the base clock output by the prescaler block.
If two sampled values are the same, the output of the match detector changes, and the data is sampled as
input data.
Because the circuit is configured as shown in Figure 14-21, the internal processing of the reception operation
is delayed by two clocks from the external signal status.
Figure 14-21. Noise Filter Circuit
Internal signal B
Internal signal A
Match detector
In
Base clock
R
X
D6/P14
Q
In
LD_EN
Q
(h) SBF transmission
When the device is incorporated in LIN, the SBF (Synchronous Break Field) transmission control function is
used for transmission. For the transmission operation of LIN, see Figure 14-1 LIN Transmission
Operation.
The TxD6 pin outputs a high level when bit 7 (POWER6) of asynchronous serial interface mode register 6
(ASIM6) is set to 1. Transmission is enabled when bit 6 (TXE6) of ASIM6 is set to 1 next time, and SBF
transmission operation is started when bit 5 (SBTT6) of asynchronous serial interface control register 6
(ASICL6) is set to 1.
After transmission has been started, the low levels of bits 13 to 20 (set by bits 4 to 2 (SBL62 to SBL60) of
ASICL6) are output. When SBF transmission is complete, a transmission completion interrupt request
(INTST6) is issued, and SBTT6 is automatically cleared. After SBF transmission is completed, the normal
transmission mode is restored.
SBF transmission is stopped until the data to be transmitted next is written to transmit buffer register 6
(TXB6) or SBTT6 is set to 1.
Figure 14-22. SBF Transmission
T
X
D6
INTST6
SBTT6
1
2
3
4
5
6
7
8
9
10
11
12
13
Stop
Remark T
X
D6: T
X
D6 pin (output)
INTST6: Transmission completion interrupt request
SBTT6: Bit 5 of asynchronous serial interface control register 6 (ASICL6)