Data Register (Idar) - Fujitsu F2MC-16LX Hardware Manual

19.3.5 Data Register (IDAR)

The data register (IDAR) reads and writes the data used for serial transmission.
■ Data Register (IDAR)
Data register
Address: ch.0 000030
ch.1 000036
Read/write
Initial value
[bit7 to bit0] D7 to D0 (Data bits)
These bits are the data register used for serial transmission, which is transferred starting
from the MSB. The data output value is 1 when data is being received (TRX = 0).
The writing side of this register is double-buffered. When the bus is in use (BB = 1), the
written data is loaded in the register for serial transmission whenever one-byte is transmitted.
The data is read directly from the register for serial transmission, which means the received
data is available when the INT bit is set.
Figure 19.3-6 Data Register (IDAR)
7 6 5
bit
H
D7 D6 D5
H
(R/W) (R/W) (R/W) (R/W) (R/W) (R/W) (R/W) (R/W)
(X) (X) (X)
19.3 Registers of the I
4 2 1
3
D4 D3 D2 D1
(X) (X) (X) (X)
2
C Interface
0
D0 IDAR
(X)
315