UPD161623 Datasheet, PDF (26/83 Pages) NEC – 528 OUTPUT TFT-LCD SOURCE DRIVER WITH RAM

µ PD161623
5.3 Oscillator
The µ PD161623 has a CR oscillator (with external R resistance), which generate the display clock. When OSCSEL is
L, an internal CR oscillator is selected. On the other hand, leave both OSCIN and OCSOUT pin open. When OSCSEL is
H, an external connection oscillator is selected. Connect 42 kΩ resistance between OSCIN an OSCOUT pin (when in
used 240 lines).
This oscillator also has a calibration function, which is available by itself to set the number of frame frequency of
display driving. Frame frequency calibration is set by calibration register (R45). The time to select one line is set by
the calibration start and stop commands.
Figure 5–14. Frame Frequency Calibration
Calibration
command
Start/Stop
Register
OSC
n-bit
counter
Internal
clock
The calibration function involves counting the number of oscillation clocks generated between the start and stop
signals and storing that number in a register. The number of oscillation clocks is then continually compared with this
register value in subsequent operations, and the time of the clock number stored in the register is set as 1 line
selection time, and used as the internal reference clock.
Using the time to set calibration (tcal) can be selected either tcal or tcal x 2 through control register 2 (R1): LTS.
Figure 5–15. Calibration Function Timing (LTS [R1] = 0)
Calibration start
OSC1
OSC2
1
2
1
tcal (1 line time)
3
4
5
2
3
Calibration stop
tcal = 1/(fFRAME x n)
fFRAME = Frame frequency
n: Line numbers
6
7
4
26
Data Sheet S15817EJ2V0DS