HD66724 Datasheet, PDF (38/117 Pages) Hitachi Semiconductor – (Graphics LCD Controller/Driver with Key Scan Function)

HD66724/HD66725
During the sleep mode, the other RAM data and instructions cannot be updated although they are retained.
STB: When STB = 1, the HD66724/HD66725 enter the standby mode, where display operation and key
scan completely stop, halting all the internal operations including the internal R-C oscillator. Further, no
external clock pulses are supplied. This setting can be used as the system wake-up, because an interrupt is
generated when a specific key is pressed. For details, refer to the Standby Mode section. Only the
following instructions can be executed during the standby mode.
a. Standby mode cancel (STB = 0)
b. Voltage follower circuit on/off (AMP = 1/0)
c. Start oscillator
d. Key scan interrupt generation enabled/disabled (IRE = 1/0)
e. Port control (PT2-0 bits)
During the standby mode, the other RAM data and instructions may be lost. To prevent this, they must be
set again after the standby mode is canceled.
R/W RS DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0 0 0 0 0 0 1 AMP SLP STB
Figure 8 Power Control Instruction
Contrast Control 1/2
SW: Switches the bit configuration for the contrast control instruction. SW = 0 corresponds to CT4 to
CT0. SW = 1 corresponds to BT1/0 and BS2 to BS0.
CT4–CT0: When SW = 0 controls the LCD drive voltage (potential difference between V1 and GND) to
adjust contrast. A 32-step adjustment is possible. For details, refer to the Contrast Adjuster section.
R/W RS DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0
0
0
00
1
0
CT4 CT3 (SW = 0)
SW _{BT1 BT0 (SW = 1)}
CT2 CT1 CT0 _{(SW = 0)}
0 0 0 0 0 1 1 _{BS2 BS1 BS0 (SW = 1)}
Figure 9 Contrast Control 1/2 Instruction
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