
HM17CM256
- 70 -
(34-19) RAM data length setting
CS
RS
RD
WR
RE
2
RE
1
RE
0
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
0
1
1
0
1
0
0
1
0
0
1
*
*
CKS
WLS
( reset :{WLS}=0
H
, read address :9
H
)
* : “Don’t care”
WLS: Selection 8 bit access or 16 bit access at RAM access. Access with 16 bits data length is effective
only at RAM access. The other accesses are 8 bits access ( command access ).
WLS=”0”: RAM access is done by 8 bits data length.
WLS=”1”: RAM access is done by 16 bits data length
CKS: Selection the oscillator.
CKS=”0”: internal oscillation mode ( default ).
Internal oscillation mode should be used under condition of OSC
1
and OSC
2
open.
CKS=”1”: external oscillation mode.
External oscillation mode should be used under the condition of clock input by OSC
1
port or resistor
connection between OSC
1
and OSC
2
port.
(34-20) Electric volume registers setting.
CS
RS
RD
WR
RE
2
RE
1
RE
0
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
0
1
1
0
1
0
0
1
0
1
0
DV
3
DV
2
DV
1
DV
0
( read address :A
H
)
CS
RS
RD
WR
RE
2
RE
1
RE
0
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
0
1
1
0
1
0
0
1
0
1
1
*
DV
6
DV
5
DV
4
( read address :B
H
)
( reset :DV
6
~DV
0
=00
H
)
* : “Don’t care”
Setting the electric volume code. The voltage range is divided into 127 levels by this register
DV
6
DV
5
DV
4
DV
3
DV
2
0
0
0
0
0
0
0
0
0
0
:
:
1
1
1
1
1
1
1
1
1
1
DV
1
0
0
1
1
DV
0
0
1
0
1
Output voltage
low
:
:
:
:
high
The output voltage of V
REG
is determined by Eq.
¥
.
V
REG
= V
REF
x N
(N: booster coefficient)
N=1 under the condition of boosting operation is not valid (booster coefficient register, VU=0
H
).
The LCD driving voltage V
LCD
is decided by V
REG
level or electric volume value (Eq.
¨
).
V
LCD
= 0.5 x V
REG
+ M x (V
REG
- 0.5V
REG
) / 127
( M : DV
6
~DV
0
register value )
¨
To prevent over voltage from being generated by electric volume setting, when the register value is set
to upper side of electric volume, voltage level is not changed immediately.
When the register value is set to lower side of electric volume, the voltage level is changed instantly.