Fujitsu FR81S User Manual
CHAPTER 40: MULTI-FUNCTION SERIAL INTERFACE
5. Operation of UART
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : MULTI-FUNCTION SERIAL INTERFACE
FUJITSU SEMICONDUCTOR CONFIDENTIAL
175
5.3.2.
Operation Mode 1 (One-to-N Connection)
In operation mode 1 (multi-processor mode), communications can be performed via master-slave
connection between multiple CPUs. UART can be used either as a master or slave.
CPU Interconnection
For master-slave communications, a communication system can be configured as one master CPU and
multiple slave CPUs connected to two common communication lines as shown in the Figure below. UART
can be used either as a master or slave.
Figure 5-22 Example of Connection for Master-Slave Communications of UART
Function Selection
For master-slave communications, select an operation mode and a data transfer method as shown in Table
5-4:
Table 5-4 Selection of Master-Slave Communication Function
Operation mode
Data
Parity
Stop bit
Bit direction
Master
CPU
Slave
CPU
Address
transmission
and reception
Mode 1
(AD bit
transmission)
Mode 1
(AD bit
reception)
AD = "1"
+
7 or 8-bit
Address
None
1 bit or 2 bits
LSB or,
MSB First
Data
transmission
and reception
AD = "0"
+
7 or 8-bit Data
Note:
Have word access to transmitted and received data (TDR/RDR) in operation mode 1.
SOT
SIN
STO SIN
STO SIN
Master CPU
Slave CPU #0
Slave CPU #1
MB91520 Series
MN705-00010-1v0-E
1488