Telegraph Length Read Register (Derr) - Fujitsu F2MC-16LX MB90580 Series Hardware Manual

13.3 Registers and Register Details

13.3.12 Telegraph length read register (DERR)

Telegraph length read register (DERR)
Address: 00007E
H
Read/write
Initial value
if the unit itself is the receiver, this register stores the number of data specified by telegraph length field.
If the unit itself is the transmitter, the telegraph length bits in telegraph length set register (DEWR) are
read. This register is set after the following.
1. When used as master unit
(a) In transmit mode, the number of transmit data bytes is written into DEWR
(b) In receive mode, the telegraph length field is received
(c) Communication ends
2. When used as slave unit
(a) In transmit mode, the number of transmit data bytes is written into DEWR
(b) In receive mode, the telegraph length field is received
(c) Communication ends
160 Chapter 13: IE Bus
7 6 5
DE7 DE6 DE5
(R) (R) (R)
(X) (X) (X)
4 3 2
DE4 DE3 DE2
(R)
(R) (R)
(X)
(X) (X)
Bit Number
1 0
DE1 DE0 DERR
(R) (R)
(X) (X)
MB90580 Series