hd66765 Renesas Electronics Corporation., hd66765 Datasheet - Page 66

• Manufacturer Part Number: hd66765
• Description: 396-channel Segment Driver With Internal Ram For 4096-color Displays - Hitachi Semiconductor
• Manufacturer: Renesas Electronics Corporation.

HD66765
Example Calculation 1
Display duty: 1/176
Retrace-line period: 0 clock (RTN3 to 0 = 0000)
Operation clock division ratio: 1 division
In this case, the CR oscillation frequency becomes 264 kHz. The external resistance value of the CR
oscillator must be adjusted to be 264 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: 3 clock (RTN3 to 0 = 0011)
Operation clock division ratio: 4 division
Example Calculation 2
(Animation display)
Frame frequency: 90 Hz
Display duty: 1/176
Retrace-line period: 0 clock (RTN3 to 0 = 0000)
Operation clock division ratio: 1 division
(Static image display)
Frame frequency: 60 Hz
Display duty: 1/176
Retrace-line period: 13 clock (RTN3 to 0 = 1101)
Operation clock division ratio: 1 division
fosc = 60 Hz (0 25) clock 1 division 176 lines = 264 (kHz)
Frame frequency = 264 kHz/ ((3 25) clock 4 division 40 lines) = 58.9 (Hz)
fosc = 90 Hz (0 25) clock 1 division 176 lines = 396 (kHz)
Frame frequency: 396 kHz/ ((13 25) clock 2 division 176 lines) = 59.2 (Hz)
Switching the frame frequency to suit animation/static image display
To set the maximum frame frequency to 60 Hz
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