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R01UH0336EJ0102 Rev.1.02
Page 1256 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 22 Synchronous/Asynchronous Serial Interface H (UARTH)
Note 4.
In order to adjust the baud-rate clock properly, the URTHnRXD signal needs to
be connected to the capture input of a timer. (For details, refer to Section 22.8,
Detecting the Baud Rate in LIN Communications as a Slave.) The transfer rate
and baud-rate error can be calculated from the measured time between two
edges of the URTHnRXD signal, and the baud rate can be adjusted
accordingly via the baud-rate setting bits (URTHnCTL2.URTHnBRS[11:0]).
Note 5.
The check-sum field is distinguished by software. UARTHn is initialized
following reception of the check-sum field, and processing to set the BF
reception mode again is performed by software. When
URTHnCTL1.URTHnSLBM = 1, BF can be received.
22.6.7
BF Transmission
Setting both the URTHnPW and URTHnTXE bits in URTHnCTL0 to 1 places
the interface in the transmission enabled state, after which BF transmission is
started by setting the BF transmission trigger (URTHnTRG.URTHnBTT) to 1.
Thereafter, URTHnSTR0.URTHnSSBT is set to "1" and the low level is output
over a width of 13 to 20 bits, as specified by URTHnCTL1.URTHnBLG[2:0].
A transmission interrupt URTHnTIT is generated
• at the start of BF transmission if URTHnCTL1.URTHnSLIT = 0 and
• at the end of BF transmission if URTHnCTL1.URTHnSLIT = 1.
Following the end of BF transmission, URTHnSTR0.URTHnSSBT is
automatically cleared. Thereafter, the UARTHn transmission mode is restored.
Transmission is suspended until the next data for transmission are written to
the URTHnTX register, or until the BF transmission trigger
(URTHnTRG.URTHnBTT) is set to 1 and URTHnSTR0.URTHnSSBT changes
to 1.
Figure 22-7
BF Transmission
URTHnSTR0.
URTHnSSBT
URTHnTIT
(URTHnSLIT = 0)
URTHnTIT
(URTHnSLIT = 1)
URTHnTRG.URTHnBTT = 1
2
3
4
5
6
7
8
9
10
1
11
12
13
Stop bit