Fujitsu 8FX Hardware Manual page 244

CHAPTER 14 LIN-UART
14.6 Operations of LIN-UART and LIN-UART
Setting Procedure Example
■ Inter-CPU Connection Method
The external clock one-to-one connection (normal mode) and the master/slave connection
(multiprocessor mode) can be selected as an inter-CPU connection method. In either method,
use the same data length, parity setting, synchronization type, etc. for CPUs. Select their
operating modes as follows.
• One-to-one connection: Use either operating mode 0 or operating mode 2 for both CPUs.
• Master/slave connection: Select operating mode 1. Use the CPU as a master/slave system.
■ Asynchronous/Synchronous Method
As for the asynchronous method, the receive clock is synchronized with the receive start bit
falling edge. As for the synchronous method, the receive clock can be synchronized with the
clock signal of the serial clock transmission side, or with the clock signal of the LIN-UART
operating as the transmission side.
■ Signaling
NRZ (Non Return to Zero).
■ Enable Transmission/Reception
The LIN-UART uses the SCR:TXE bit and the SCR:RXE bit to control transmission and
reception, respectively. Execute the following operations to disable transmission or reception.
• To disable reception while it is in progress: wait until reception ends, read the receive data
register (RDR), then disable reception.
• To disable transmission while it is in progress: wait until transmission ends, then disable
transmission.
■ Setting Procedure Example
Below is an example of procedure for setting the LIN-UART.
● Initial settings
1. Set the port input. (DDR)
2. Set the interrupt level. (ILR*)
3. Set the data format and enable transmission/reception. (SCR)
4. Select the operating mode and the baud rate, and enable pin output. (SMR)
5. Set the baud rate generators 1, 0. (BGR1,BGR0)
*: For details of the interrupt level setting register (ILR), refer to "CHAPTER 5 INTERRUPTS" in this
hardware manual and "■ INTERRUPT SOURCE TABLE" in the device data sheet.
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Select the operating mode 0 for asynchronous method or the
operating mode 2 for synchronous method. In addition, in
operating mode 2, set one CPU as the transmission side of serial
clock and the other as the reception side of serial clock.
FUJITSU SEMICONDUCTOR LIMITED
MB95630H Series
MN702-00009-2v0-E