Fujitsu F2MCTM-16LX Hardware Manual page 433

Using external clock
If the EXT bit of the SMR is set to 1, an external clock is selected, which has to be connected to the SCKn
pin. The external clock is used in the same way as the internal clock to the baud rate generator.
If One-to-one External Clock Input Mode (SMR: OTO=1) is selected the SCKn signal is directly connected
to the LIN-UART serial clock inputs. This is needed for the LIN-UART synchronous mode 2 operating as
slave device.
Note:
In any case the resulting clock signal is synchronized to the internal clock in the LIN-UART module.
This means that indivisible clock rates will result in phase unstable signals.
Counting Example
Assume the reload value is 832. Figure 20.6-2 demonstrates the behavior of both Reload Counters:
Figure 20.6-2 Counting Example of the Reload Counters
Transmission/Reception Clock
Reload
001
Counter
Transmission/Reception Clock
Reload
417
Counter
Note:
The falling edge of the Serial Clock Signal always occurs after | (v + 1) / 2 |.
000 832 831
Reload counter value
416 415 414
830 829 828
413 412 411
CHAPTER 20 LIN-UART
827
410
417