SNL320
16-Bit LCD Controller
5.5 Watch Mode
This mode is for some real time clock application, users have to add a 32768HZ crystal
to realize RTC function. Considering to saving power consumption, user should stop
the hi-speed clock source (16MHZ) and enable the low-speed clock source. Then chip
will entry power down mode but the low-speed clock still working and wake-up chip
once the RTC period is happened in order to fresh the RTC timer.
There are four options for RTC interrupt period, users can select 0.25sec/0.5sec and
1sec through the RTC control register.
If chip is in power-down mode and interrupt enable is active for RTC, then chip will be
wake-up from power-down mode per 0.25/0.5/1 second.
6.
POWER ON RESET
When “L” level appears on RESET PIN, the chip will enter RESET state.
After reset, the chip does not execute the first instruction until counting 2
17
clock cycles.
It takes around 8.2ms at 16MHz. (crystal for clock source), and the location of the first
instruction after RESET is 0x000000. In additional, all the contents of SRAM will be
unchanged during RESET stage.
7.
I/O PORT
SNL320 provides totally 36 I/O pins (P1.0~P1.15, P3.0~P3.15, P4.0~P4.3). The
input pull-high resistor of each pin can be programmed by port pull-high register and
the direction of I/O port is selected by port direction register. The I/O port P1.0~P1.15
can wake the chip up from the stop mode and watch mode.
These 36 programmable I/O pins provides not only a simply input/output function but
also can configure to be chip select pins of extension bus, LCD driver interface and
NAND flash interface. For the detail please refer to following sections.
The internal structure of I/O pins is showed in
Figure-2.
Ver: 1.2
9
July 22, 2005
SONIX [ SONIX TECHNOLOGY COMPANY ]
