ST STM32L496 Series

DocID029937 Rev 2 19/22
AN4943 New DMA2D features to support Intel 8080 displays
21
5.3.3 16bpp over 8-bit FSMC data bus interface
In order to drive the 16bpp Intel 8080 display over an 8-bit interface, the MSB and LSB
bytes of a half word must be swapped.
Figure 10 shows how the swap operation allows having the good bytes order.
Figure 10. DMA2D operations to support 16bpp over 8-bit interface
MSv48352V1
@+0
@+1
@+2
@+3
Memory
Pixel 0
Pixel 1
8-bit FSMC data bus
1
234
Transfer
number
D7
D6
D5
D4
D3
D2
D1
D0
R0 [4]
R0 [3]
R0 [2]
R0 [1]
R0 [0]
G0 [5]
G0 [4]
G0 [3]
G0 [2]
G0 [1]
G0 [0]
B0 [4]
B0 [3]
B0 [2]
B0 [1]
B0 [0]
R1 [4]
R1 [3]
R1 [2]
R1 [1]
R1 [0]
G1 [5]
G1 [4]
G1 [3]
G1 [2]
G1 [1]
G1 [0]
B1 [4]
B1 [3]
B1 [2]
B1 [1]
B1 [0]
R0 [4]
R0 [3]
R0 [2]
R0 [1]
R0 [0]
G0 [5]
G0 [4]
G0 [3]
G0 [2]
G0 [1]
G0 [0]
B0 [4]
B0 [3]
B0 [2]
B0 [1]
B0 [0]
R1 [4]
R1 [3]
R1 [2]
R1 [1]
R1 [0]
G1 [5]
G1 [4]
G1 [3]
G1 [2]
G1 [1]
G1 [0]
B1 [4]
B1 [3]
B1 [2]
B1 [1]
B1 [0]
Byte swap
R0 [4]
R0 [3]
R0 [2]
R0 [1]
R0 [0]
G0 [5]
G0 [4]
G0 [3]
G0 [2]
G0 [1]
G0 [0]
B0 [4]
B0 [3]
B0 [2]
B0 [1]
B0 [0]
R1 [4]
R1 [3]
R1 [2]
R1 [1]
R1 [0]
G1 [5]
G1 [4]
G1 [3]
G1 [2]
G1 [1]
G1 [0]
B1 [4]
B1 [3]
B1 [2]
B1 [1]
B1 [0]
Pixel 0 Pixel 1
@+0
@+1
@+2
@+3
Green component
Red component
Blue component