st2604b Sitronix Technology Corporation, st2604b Datasheet - Page 31

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

< Standard flow for switching I/O and segment >
We know that there are many I/O which are shared with LCD segment.
And the configure is determined by LCFG register.
Here is the standard flow of configure I/O or segment, please follow up. Or programmer will not configure I/O possibly.
(1) Please configure LCFG first!!
(2) And then configure PCA/PCB/PCC/PCD/PCE/PCL
(3) Finally configure PA/PB/PC/PD/PE/PL
Sample code:
< LCDCK=32K with cascade mode >
There has some limit when programmer use LCDCK=32K and cascade.
Programmer can use ST26 with LCD cascade mode, it's no doubt. Also, programmer can use cascade mode
combine with LCDCK from 32KHz(OSCX).
But user should take care one thing as following:
We know ST26 can support Cascade 1/2/4-bit data bus mode, however, LCDCK=32K function can only support
8-bit mode!!
So, when programmer use these two functions in the same time, MCU will push 8-bit data per clock cause
LCDCK=32K function, but cascade mode maximum push 4-bit data out to LCD driver per clock, so you will lose
4-bit data(bit4~bit7) and make display data wrong.
The solution is to modify the picture, let MCU push 8-bit every clock, and we separate it every 4-bit data into 8 bit
data as picture 2. and we can solve it. Mention that because LCDCK=32K can maximum load 36 x 80 dots picture, by
above condition, we finally can push 36x40 dots picture to show on LCD since we only use half of data (first 4-bit).
Notice:
< User Manual for ST2600B external bus usage >
[Description]
Since users may use external memory bus to access external ROM, FLASH, or LCD driver, we draw this manual to tell the
bit0~bit7
LDA
STA
STA
STA
ST26xxB can only output common signal when cascade mode.
User can not mix the segment from ST26xxB and the segment from other LCD drivers. It’ s because the LCD
driving ability of ST26xxB and other LCD drivers are not the same. If user mix them, the performance of LCD display
may be bad. (Color block or cross-talk)
bit8~bit15 bit16~bit23
#FFH
LCFG
PCL
PL
; configure PL as output
; enable all I/O
; PL0~PL7 high status
ßThe original picture information
31/33
ßpicture 2 : modified picture
ST2604B