7751 Datasheet, PDF (460/540 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER

APPENDIX
Appendix 3. Control registers
Appendix 3. Control registers
The register structure of each control register assignment in the SFR area are shown on the following pages.
The view of the register structure is described below.
b7 b6 b5 b4 b3 b2 b1 b0
!0
V1
XXX register (Address XX16)
V2
V3
Bit
Bit name
Functions
0 ... select bit
0 : ...
1 : ...
1 ^{... select bit}
0 : ...
1 : ...
The value is “0” at reading.
2 ... flag
3 Fix this bit to “0.”
0 : ...
1 : ...
4 This bit is ignored in ... mode.
7 to 5 Nothing is assigned.
At reset RW
0 _RW
Undefined _WO
0 RO
0 _RW
0 RW
Undefined –
V1
V4
Blank : Set to “0” or “1” to according to the usage.
0
: Set to “0” at writing.
1
: Set to “1” at writing.
!
: Ignored depending on the specific mode or state. It may be either “0” or “1.”
: Nothing is assigned.
V2
0
: “0” immediately after a reset.
1
: “1” immediately after a reset.
Undefined : Undefined immediately after a reset.
V3
RW
: It is possible to read the bit state at reading. The written value becomes valid.
RO
: It is possible to read the bit state at reading. The written value becomes invalid. Accordingly, the written
value may be “0” or “1.”
WO
: The written value becomes valid. It is impossible to read the bit state. The value is undefined at reading.
However, when [“0” is at reading”] is indicated in the “Function” or “Note” column, the bit is always “0” at
reading. (See V4 above.)
—
: It is impossible to read the bit state. The value is undefined at reading.
However, when [“0” is at reading”] is indicated in the “Function” or “Note” column, the bit is always “0” at
reading. (See V4 above.)
The written value becomes invalid. Accordingly, the written value may be “0” or “1.”
7751 Group User’s Manual
20–9