RS_Color liquid crystal display controller (CLCD)
RM0082
754/844
Doc ID 018672 Rev 1
33.6.7
LCD timing 3 register
LCDTiming3 is a read/write (RW) register that controls the enabling of line-end signal CLLE.
When enabled, a positive pulse, four CLCDCLK periods wide, is output on CLLE after a
programmed delay set by the LED bits. If the line-end signal is disabled then it is held
permanently LOW.
33.6.8 LCDUPBASE
and
LCPLPBASE registers
LCDUPBASE and LCDLPBASE are the color LCD DMA frame address registers.
[04:00]
PCD_LO
5’h0
Lower five bits of panel clock divisor.
(1)
The ten bit PCD field,
comprising PCD_HI (bits [31:27]) and PCD_LO, is used to
derive the LCD panel clock frequency
CLCP
from the CLCDCLK
frequency,
CLCP
=
CLCDCLK
/(PCD+2).
For mono STN displays with a four or eight bit interface, the
panel clock is a factor of four and eight down on the actual
individual pixel clock rate.
For color STN displays, 2
2/3
pixels are output per
CLCP
cycle, so
the panel clock is 0.375 times. You can bypass the pixel clock
divider for TFT displays by setting the LCDTiming2[26] BCD bit.
1.
The data path latency forces some restrictions on the usable minimum values for the panel clock divider in
STN modes:
Single-panel color mode: PCD = 1 (CLCP = CLCDCLK/3)
Dual-panel color mode: PCD = 4 (CLCP = CLCDCLK/6)
Single-panel mono 4 bit interface mode: PCD = 2 (CLCP = CLCDCLK/4)
Dual-panel mono 4 bit interface mode: PCD = 6 (CLCP = CLCDCLK/8)
Single- panel mono 8 bit interface mode: PCD = 6 (CLCP = CLCDCLK/8)
Dual-panel mono 8 bit interface mode: PCD = 14 (CLCP = CLCDCLK/16)
Table 678.
LCDTiming2 register bit assignments (continued)
Bit
Name
Reset
value
Description
Table 679.
LCDTiming3 register bit assignments
Bit
Name
Reset
value
Description
[31:17]
-
-
Reserved, do not modify, read as zero, write as
zero.
[16]
LEE
1’h0
LCD Line end enable:
1’b0 =
CLLE
disabled (held LOW)
1’b1 =
CLLE
signal active.
[15:07]
-
-
Reserved, do not modify, read as zero, write as
zero
[06:00]
LED
7’h0
Line-end signal delay from the rising-edge of the
last panel clock,
CLCP
. Program with number of
CLCDCLK
clock periods minus 1.