Digi NS9750 Manual de usuario descargar pdf (Pagina 82)

Clock timing

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NS9750B-A1 Datasheet 03/2006

Clock timing

Clock AC characteristics are measured with 10pF, unless otherwise noted.

The next three timing diagrams pertain to clock timing.

USB crystal/external oscillator timing

Table 40 describes the values shown in the USB crystal/external oscillator timing diagram.

Note:

1 If using a crystal, the tolerance must be ±100 ppm or better.

LCD input clock

Table 41 describes the values shown for the LCD input clock timing diagram.

Note:

1 The clock rate supplied on lcdclk is twice the actual LCD clock rate.

Parameter Description Min Max Unit Notes

UC1 x1_usb_osc cycle time 20.831 20.835 ns 1

UC2 x1_usb_osc high time (UC1/2) x 0.4 (UC1/2) x 0.6 ns

UC3 x1_usb_osc low time (UC1/2) x 0.4 (UC1/2) X 0.6 ns

Table 40: USB crystal/external oscillator timing parameters

Parameter Description Min Max Unit Notes

LC1 lcdclk cycle time 6.25 ns 1

LC2 lcdclk high time (LC1/2) x 0.4 (LC1/2) x 0.6 ns

LC3 lcdclk low time (LC1/2) x 0.4 (LC1/2) x 0.6 ns

Table 41: LCD input clock timing parameters

UC1

UC2UC2 UC3

UC1

UC3

x1_usb_osc

LC2

LC1

LC2 LC3

LC1

LC3

lcdclk

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Digi NS9750 Manual de usuario Pagina 82