3886 datasheet(246/380 Pages) RENESAS

246 / 380 page

3886 Group User’s Manual

APPLICATION

2-129

2.9 Bus interface

Fig. 2.9.2 Structure of Data bus buffer register i

2.9.2 Relevant registers

Fig. 2.9.3 Structure of Data bus buffer status register i

Data bus buffer register i

b7b6b5b4b3b2b1b0

Function

At reset

Name

Data bus buffer register i (DBBi) (i=0, 1) [Address : 2816/2B16]

• Buffer register to write output data and read input data.

• at write: data is written to output data buffer register.

• at read: the contents of input data buffer register are read out.

Note: Output data bus buffer and input data bus buffer are assigned to the same address.

The contents of output data bus buffer register cannot be read out.

Writing to input data bus buffer register is disabled.

Data bus buffer status register i

b7b6b5b4b3b2b1b0

Function

At reset RW

Name

Output buffer full flag i

Input buffer full flag i

0 : Buffer empty

1 : Buffer full

User definable flags (This flag can be defined by user freely.)

A0i flag

User definable flags (This flag can be defined by user freely.)

0 : Buffer empty

1 : Buffer full

This flag indicates the condition of

A0i status when the IBFi flag is set.

Data bus buffer status register i (DBBSTSi) (i=0, 1) [Address 2916/2C16]

3886 Datasheet(PDF) 246 Page - Renesas Technology Corp