CHAPTER 19 IEBus CONTROLLER (V850/SB2)
User’s Manual U13850EJ4V0UM
465
Figure 19-20. IEBus Telegraph Length Register (DLR) Format
After reset: 01H
R/W
Address: FFFFF3EAH
7
6
5
4
3
2
1
0
DLR
Bit
7
6
5
4
3
2
1
0
Setting
value
Remaining number of
communication data bytes
0
0
0
0
0
0
0
1
01H
1 byte
0
0
0
0
0
0
1
0
02H
2 bytes
:
:
:
:
:
:
:
:
:
:
0
0
1
0
0
0
0
0
20H
32 bytes
:
:
:
:
:
:
:
:
:
:
1
1
1
1
1
1
1
1
FFH
255 bytes
0
0
0
0
0
0
0
0
00H
256 bytes
Cautions 1. If the master issues a request “0H, 4H, 5H, or 6H” to transmit a slave status and lock
address (higher 4 bits, lower 8 bits), the contents of this register are set to “01H” by
hardware; therefore, the CPU does not have to set this register.
2. In the case of defeat in a bus conflict and a slave status request is received from the unit
that won, DLR is fixed to “01H”. Therefore, if a re-request of the master follows, the
appointed telegraph length must be set to DLR.