st2604b Sitronix Technology Corporation, st2604b Datasheet - Page 22

• Manufacturer Part Number: st2604b
• Description: 8-bit Integrated Microcontroller
• Manufacturer: Sitronix Technology Corporation

<Methods to make up LCD voltage deviation >
Notice1:
Notice2:
Notice3:
<Vertical Cross talk on LCD display>
Description:
Solution:
In order to cover the variation of VLCD of LCD panel, be sure to reserve pin-option by GPIO to
Verifying the performance of voice on ST2602/2604/2608 DEMO boards.
Programmer should add a contrast controller function to adjust VLCD for the convenience of
change the status of VLCD( bit0:3 of register LREG). Here we suggest that there are at least
5-level of voltage pin-option for VLCD. If the GPIO is not enough to make pin-option,
programmer can use key-return-line method for power on pin-option.
end-user to change the contrast as they like.
can not provide the totally voice efficacy, such like the volume and the quality of voice. So we strongly
suggest to verify voice playing on ST2602B/ST2608B DEMO boards before MASK.
(Ps… Because LCD SEG pins are shared with external EPROM, so the picture can not be verified on
DEMO boards.)
Vertical cross talk usually happens when the differential voltage of V0~V4 are not closely. In this case,
increase C0~C4 (recommend > 1uF) will eliminate this problem. Fine tuning the value of capacitance
to get the best LCD quality.
For example: make pin-option for change VLCD at… /5.6/5.8/6.0V/6.2V/6.4/…
contrast… /5.8/5.9V/6.0V/6.2V/6.2V/6.3/6.4/… by using contrast controller function.
Vertical Cross talk on LCD display
For example: VLCD is pre-set at 6.2 by pin-option, end-users can also adjust the
22/33
Because ST2600B DVB
ST2604B