參數(shù)資料
型號: HD667A66R
廠商: Hitachi,Ltd.
英文描述: 132 x 176-dot Graphics LCD Controller/Driver for 65K Colors
中文描述: 132 × 176點圖形LCD控制器/驅(qū)動器的65K色
文件頁數(shù): 68/97頁
文件大小: 681K
代理商: HD667A66R
HD66766R Rev. 1.0-1 / September 2002
68
Frame-Frequency Adjustment Function
The HD66766R has an on-chip frame-frequency adjustment function. The frame frequency can be
adjusted by the instruction setting (DIV, RTN) during the LCD drive as the oscillation frequency is
always the same. When the display duty is changed, the frame frequency can be adjusted to be the same.
If the oscillation frequency is set to high, an animation or a static image can be displayed in suitable ways
by changing the frame frequency. When a static image is displayed, the frame frequency can be set low
and the low-power consumption mode can be entered. When high-speed screen switching, for an
animated display, etc. is required, the frame frequency can be set high.
Relationship between LCD Drive Duty and Frame Frequency
The relationship between the LCD drive duty and the frame frequency is calculated by the following
expression. The frame frequency can be adjusted in the retrace-line period bit (RTN) and in the
operation clock division bit (DIV) by the instruction.
(Formula for the frame frequency)
fosc
Frame frequency =
Clock cycles per raster-row
×
division ratio
×
1/duty cycle
[Hz]
fosc: R-C oscillation frequency
Duty: drive duty (NL bit)
Clock cycles per raster-row: (RTN + 26) clock cycles
Division ratio: DIV bit
Example Calculation 1
Setting the maximum frame frequency to 60 Hz
Display duty: 1/176
Retrace-line period: 0 clock (RTN3-0 = “0000”)
Operation clock division ratio: 1 division
fosc = 60 Hz
×
(0
+
26) clock
×
1 division
×
176 lines = 275 (kHz)
In this case, the R-C oscillation frequency becomes 275 kHz. The external resistance value of the R-C
oscillator must be adjusted to be 275 kHz. The display duty can be changed by the partial display, etc. and
the frame frequency can be the same by setting the RNT bit and DIV bit to achieve the following.
(Partial display): Display duty: 1/40
Retrace-line period: 1 clock (RTN3-0 = “0002”)
Operation clock division ratio: 3 division
Frame frequency = 275 kHz/ ((3
+
26) clock
×
4 division
×
40 lines) = 59.2 (Hz)
Example Calculation 2
Switching the frame frequency to suit animation/static image display
(Animation display): Frame frequency: 90 Hz
Display duty: 1/176
Retrace-line period: 0 clock (RTN3-0 = “0000”)
Operation clock division ratio: 1 division
fosc = 90 Hz
×
(0
+
26) clock
×
1 division
×
176 lines = 412 (kHz)
(Static image display): Frame frequency: 90 Hz
Display duty: 1/176
Retrace-line period: 1 clock (RTN3-0 = “1101”)
Operation clock division ratio: 1 division
Frame frequency: 412 kHz/ ((13
+
26) clock
×
1 division
×
176 lines) = 60.0 (Hz)
相關(guān)PDF資料
PDF描述
HD667B66R 132 x 176-dot Graphics LCD Controller/Driver for 65K Colors
HD66780FH LAMPS, STACKABLE INDICATOR
HD66780FS Dot Matrix Liquid Crystal Display Controller and Driver
HD66780 Dot Matrix Liquid Crystal Display Controller and Driver
HD66841 LVIC-II (LCD Video Interface Controller)(LCD視頻控制器)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
HD667B66R 制造商:HITACHI 制造商全稱:Hitachi Semiconductor 功能描述:132 x 176-dot Graphics LCD Controller/Driver for 65K Colors
HD66840 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Peripheral IC
HD66840F25 制造商:未知廠家 制造商全稱:未知廠家 功能描述:LCD Controller
HD66840F30 制造商:未知廠家 制造商全稱:未知廠家 功能描述:LCD Controller
HD66841FP 制造商:未知廠家 制造商全稱:未知廠家 功能描述:LCD Controller