Fujitsu 8FX Hardware Manual page 242

CHAPTER 14 LIN-UART
14.5 LIN-UART Baud Rate
Figure 14.5-3 Example of Using a Simple Timer by Restarting the Reload Timer
MCLK
(Machine clock)
SMR register
REST bit
write signal
Reload counter
BGR0/BGR1 register
read signal
Register read value
The number of machine clock cycles "cyc" after the restart in this example is obtained by the
following equation.
Note:
The transmit reload counter restarts also when the LIN-UART is reset by writing "1" to the
SMR:UPCL bit.
Automatic restart (receive reload counter only)
The receive reload counter restarts when the start bit falling edge is detected in
asynchronous mode. This automatic restart function is to synchronize the receive shift
register with the received data.
● Clear counter
When a reset occurs, the reload values in the LIN-UART baud rate generator registers 1, 0
(BGR1, BGR0) and the reload counter are cleared to "0x00", and the reload counter stops.
Although the counter value is temporarily cleared to "0x00" by the LIN-UART reset (writing
"1" to SMR:UPCL), the reload counter restarts since the reload value is kept.
If the restart setting is used (writing "1" to SMR:REST), the reload counter restarts without the
counter value being cleared to "0x00".
220
Write
Reload
37 36 35 100 99 98 97 96 95 94 93 92 91 90 89 88 87
cyc = v - c + 1 = 100 - 90 + 1 = 11
v: Reload value, c: Reload counter value
FUJITSU SEMICONDUCTOR LIMITED
MB95630H Series
90
: No effect on operation
MN702-00009-2v0-E