Rainbow Electronics W90P710CDG - Manual (Page 282)

W90P710CD/W90P710CDG
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Fig. 6.10.5.7 FIFO parameter example
If there is an image with size 480*480, 24bpp, stored in memory device with starting address is
0x30000000, and connected with a 480*480 LCD Panel, and user wants to show whole image on
LCD Panel, the setting of registers are:
FIFO1SADDR
= 0x30000000
FIFO1COLCNT = 0x01E0
FIFO1ROWCNT = 0x01E0
FIFO1REALCOLCNT = 0x01E0
If the LCD Controller connected with a 240*240 LCD Panel or user only wants to show a part (red line
region, 240*240) of the whole image on a 480*480 LCD Panel, the setting of registers are:
FIFO1SADDR
= 0x3001C3E0 (0x30000000 + 4*(480*60+120) = 0x3001C3E0)
FIFO1COLCNT = 0x00F0
FIFO1ROWCNT = 0x00F0
FIFOSTRIDE = 0x03C0 (240*4 = 0x03C0)
FIFO1REALCOLCNT = 0x00F0
After setting register complete, enable FIFO and then FIFO will fetch the image data according to the
register value. In additional, if the image in FIFO is small than the LCD Panel, DISPWYS, DISPWXS,
DISPWYE, DISPWXE must be configured.
Usually, FIFO Real Column Count is the same with FIFO Column Count. But if horizontal down-
scaling function is enabled (factor M is not equal with N), FIFO Real Column Count specify the column
count of original image, and FIFO Column Count specify the column count of the scaled image.
If There is a picture with N BPP and horizontal width X pixel, the word-count W of this picture is:
480 pixels
480 pixels