ST STM32L496 Series, Примечание к применению, Страница: 10 / 22

LCD-TFT display on FSMC AN4943
10/22 DocID029937 Rev 2
Figure 4. Automatic control of LCD-TFT display data/command by FSMC interface
1. ‘x’ as high as possible according Table 4 .
For example, if the image buffer size is 240x240 pixels and the transfer is done using 16 bits
in RGB565 mode (one pixel transferred per access to LCD), the number of accesses are
240x240 = 57600 accesses and the FSMC address increments from 0x0000 0000 to
0x0000 E0FF.
Thus the 1
st
address bit that does not change during the transfer is the bit 16.
In this specific case the FSMC_A16 or a higher address bit can be used.
Table 4 shows the minimum FSMC address bit that can be used depending on some image
size.
Table 4. Minimum usable FSMC address bit depending on image size (16 bit RGB565
access )
Image size Nb of pixels Nb of accesses Max address
Min usable FSMC
address bit
VGA 640x480 307200 0x4AFFF FSMC_A19
HVGA 480x320 153600 0x257FF FSMC_A18
QVGA 320x240 76800 0x12BFF FSMC_A17
- 240x240 57600 0x0E0FF FSMC_A16
MSv44237V1
LCD-TFT display
FSMC_D[15:0]
Data[15:0]
Data/command selection
FSMC_A[x]
Other control signals
(1)