EP7212 Datasheet, PDF (79/136 Pages) Cirrus Logic – HIGH-PERFORMANCE, LOW-POWER SYSTEM-ON-CHIP WITH LCD CONTROLLER AND DIGITAL AUDIO INTERFACE(DAI)

EP7212
5.10 LCD Registers
5.10.1 LCDCON — The LCD Control Register
ADDRESS: 0x8000.02C0
31
GSMD
30
GSEN
29:25
AC prescale
24:19
Pixel prescale
18:13
Line length
12:0
Video buffer size
The LCD control register is a 32-bit read / write register that controls the size of the LCD screen and
the operating mode of the LCD controller. Refer to the system description of the LCD controller for
more information on video buffer mapping.
The LCDCON register should only be reprogrammed when the LCD controller is disabled.
Bit
0:12
13:18
Description
Video buffer size: The video buffer size field is a 13-bit field that sets the total number of bits x
128 (quad words) in the video display buffer. This is calculated from the formula:
Video buffer size = (Total bits in video buffer / 128) – 1
i.e., for a 640 x 240 LCD and 4 bits-per-pixel, the size of the video buffer is equal to
614400 bits.
Video buffer = 640 x 240 x 4=614400 bits
Video buffer size field = (614400 / 128) – 1 = 4799 or 0x12BF hex.
The minimum value allowed is 3 for this bit field.
Line length: The line length field is a 6-bit field that sets the number of pixels in one complete
line. This field is calculated from the formula:
line length = (Number of pixels in line / 16) – 1
i.e., for 640 x 240 LCD Line length = (640 / 16) – 1 = 39 or 0x27 hex.
The minimum value that can be programmed into this register is a 1 (i.e., 0 is not a legal value).
Table 47. LCDCON
DS474PP1
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