STM32F4 / FSMC Reading pixel of SSD1963 problem

[swing82]

Posted on January 12, 2015 at 17:35

The problem is

this:

When reading

FSMC

value

always

returns the previous

value

written

in the

FSMC

.

And

you need

a color value

of the pixel

SSD1963 ...

Actually,

what's the catch

???

reads

as:

#define LCD_REG      (*((volatile unsigned short *) 0x60000000)) #define LCD_RAM      (*((volatile unsigned short *) 0x60020000)) //0x2E read_memory_start LCD_Write_Com(0x2E); rtk[0]=LCD_RAM; //

All values

rtk []

are the same

, i.e.,

that

has been recorded

last time

(LCD_Write_Com (0x2E))

rtk[1]=LCD_RAM; rtk[2]=LCD_RAM; rtk[3]=LCD_RAM;

[Tesla DeLorean]

Posted on January 12, 2015 at 19:03

Actually,

what's the catch

???

Is there READ pin on the interface, is that correctly wired up and configured? Can you read back any of the control registers?

[swing82]

Posted on January 12, 2015 at 19:40

Write Registers

work

.

initializing

the display

is normal.

graphics primitives

fully working

.

just do not

read

...

[Tesla DeLorean]

Posted on January 12, 2015 at 20:20

Write Registers

work

.

initializing

the display

is normal.

graphics primitives

fully working

.

just do not

read

...

That would seem to constrain your task to the hardware, and peripheral configuration related to the read operation. Start your design review there.