Uart Operations - Fujitsu MB90480 Series Hardware Manual

19.5 UART Operations

This section describes the operations of the UART.
■
Operation modes
UART has the operation modes shown below. The modes can be changed by setting values in
the SMR and SCR registers.
Mode Parity
Provided/not provided
0
Provided/not provided
1 None
2 None
*1: The "+1" term represents the address/data selection bit (A/D) used in communication control.
*2: Only one bit can be detected as stop bit during reception.
The stop bit length in asynchronous (start-stop synchronization) mode can only be specified for
send operations. The bit length in reception operations is always one bit. Do not set the stop bit
length other than asynchronous (start-stop synchronization) mode.
UART operation mode 1 is used only for the master in master/slave connection.
❍ Connection between CPUs
1:1 connection (normal mode) or master/slave connection (multiprocessor mode) can be
selected. The data length, whether add or not to add a parity bit and synchronization etc. for
these two systems must be the same across all CPUs. The following operation modes can be
selected:
• In 1:1 connection (normal mode), the same operation mode, either operation mode 0 or
operation mode 2, must be selected for both CPUs.
Select operation mode 0 for asynchronous operation. Select operation mode 2 for synchronous
operation.
• In master/slave connection (multiprocessor mode), use operation mode 1. Select operation
mode 1 and use this device as the master. For this type of connection, select "no parity".
Data length Operation mode
7 Asynchronous (start-stop
synchronization) normal
8
mode
Asynchronous (start-stop
*1
8 + 1 synchronization)
multiprocessor mode
8 CLK synchronous mode
CHAPTER 19 UART
Stop bit length
*2
1 bit or 2 bits
None
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