
CHAPTER 18 IEBus CONTROLLER
User’s Manual U17790EJ2V0UD
681
(7) IEBus unit address register (UAR)
The UAR register sets the unit address of an IEBus unit. This register must always be set before starting
communication.
Sets the unit address (12 bits) to bits 11 to 0.
This register can be read or written in 16-bit units.
Reset sets this register to 0000H.
15
0
14
0
13
0
12
0
UAR
11 10
9
8
7
6
5
4
3
2
1
0
Address
FFFFF366H
After reset
0000H
R/W
Caution
Do not set the UAR register while communication is enabled (BCR.ENIEBUS bit = 1).
(8) IEBus slave address register (SAR)
During a master request, the value of this register is reflected in the value of the transmit data in the slave
address field. The SAR register must always be set before starting communication.
The SAR register sets the slave address (12 bits) to bits 11 to 0.
This register can be read or written in 16-bit units.
Reset sets this register to 0000H.
15
0
14
0
13
0
12
0
SAR
11 10
9
8
7
6
5
4
3
2
1
0
Address
FFFFF368H
After reset
0000H
R/W
Caution
Do not set the SAR register while communication is enabled (BCR.ENIEBUS bit = 1).
(9) IEBus partner address register (PAR)
The PAR register stores the master address value received in the master address field regardless of whether
the unit is operating as the master or a slave.
If a request “4H” to read the lock address (lower 8 bits) is received from the master, read the value of this
register by software, and write the data of the lower 8 bits to the DR register.
If a request “5H” to read the lock address (higher 4 bits) is received from the master, read the value of this
register by software and write the data of bits 11 to 8 to the higher 4 bits of the DR register.
The PAR register sets the partner address (12 bits) to bits 11 to 0.
This register is read-only, in 16-bit units.
Reset sets this register to 0000H.
15
0
14
0
13
0
12
0
PAR
11 10
9
8
7
6
5
4
3
2
1
0
Address
FFFFF36AH
After reset
0000H
R/W
R
Caution
The PAR register stores an address value if the parity is correct and the unit is not locked
when the parity period of the master address field expires. If the PAR register is read at
this time, an undefined value is read.