SNL320

16-Bit LCD Controller

5.1

Normal Mode

The normal mode means CPU main clock source is comes from 16MHZ Rosc or

crystal hi-speed clock source, so SNL320 is run in full speed. There are two pins option

“CKSEL” and “PLLEn” to select Rosc/crystal and enable/disable PLL circuit.

The detail setting of hi-speed clock is shown as following table.

CKSEL

PLLEn

Descriptions

0

0

16MHZ X’tal for hi-speed clock source

0

1

6MHZ X’tal and pumping to 16MHZ for hi-speed

clock source. (for USB application)

1

0

16MHZ Rosc for hi-speed clock source

1

1

reserved

5.2

Low-speed mode

This is a special operation mode of SNL320, the hi-speed clock is disable and main

clock of SNL320 is comes from low-speed clock source (32768HZ). It will save more

power consumption when chip works on this low-speed mode and this low-speed clock

can select 32768HZ crystal for clock source.

In additional, this low-speed clock also used to calibrate the hi-speed clock once the

high-speed clock source is comes from Rosc.

5.3

Stop Mode

In stop mode, all the system clocks are stop (16MZH & 32768HZ) and chip entry a very

low power consumption state. Chip will wake-up from stop mode once any IO state

change or external interrupt occurs.

5.4

Suspend Mode

In suspend mode, the hi-speed clock still working but chip is hold until any IO toggle or

external interrupt occurs. That means, the power consumption only come from

HXOSC circuit and LCD driver interface refresh circuit.

Ver: 1.2

8

July 22, 2005