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CHAPTER 14 SERIAL INTERFACE UART6
User’s Manual U19780EJ2V0UD
392
(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/P11
Q
In
LD_EN
Q
(h) SBF transmission
When the device is use in LIN communication operation, 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
.
When bit 7 (POWER6) of asynchronous serial interface mode register 6 (ASIM6) is set to 1, the T
X
D6 pin
outputs high level. Next, when bit 6 (TXE6) of ASIM6 is set to 1, the transmission enabled status is entered,
and SBF transmission is started by setting bit 5 (SBTT6) of asynchronous serial interface control register 6
(ASICL6) to 1.
Thereafter, a low level of bits 13 to 20 (set by bits 4 to 2 (SBL62 to SBL60) of ASICL6) is output. Following
the end of SBF transmission, the transmission completion interrupt request (INTST6) is generated and
SBTT6 is automatically cleared. Thereafter, the normal transmission mode is restored.
Transmission is suspended until the data to be transmitted next is written to transmit buffer register 6 (TXB6),
or until 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)