SNL310

16-Bit LCD Controller

The modulation function will be active when the control bit “IREN” set to “1”. And

setting timer2 can generate the frequency of carry signal.

5. TIMER/COUNTER

SNL310 provides three 8-bit timer/event counters (T0/T1/T2). Each timer is 8-bit

binary up-count timer with pre-scalar and auto-reload function. Timer 0 (T0) was

used when voice playing, so user should avoid to use T0.

(system clock)/2*

Auto-reload

clear

comparator

MUX

/256

/8

/4

/2

If equal, Time out

8-bit Up

Counter

Enable

Pre-scalar

TnC (8-bit)

Figure-4

6. Real Time Clock (RTC)

To realize the watch function, 0.25s RTC (real time clock) is built in the chip. The real

time clock has two clock sources. One is from system clock (16MHZ) and another one

is from low-speed clock source (32768HZ). Once the RTC function is enabled, the

RTC circuit will generate an interrupt request per 0.25 second.

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 second.

7. DA & PWM

To play out voices, SNL310 contains two different solutions for the user’s

applications, DAC and PWM. The user can choose one of these two solutions in this

design. Only one function can be activated at one time.

7.1 DAC

A 10-bit current type digital-to-analog converter is built-in SNL310. The relationship

between input digital data and output analog current signal is listed in the following

table. Also, the recommended application circuit is illustrated as follows.

Ver: 1.7

May 2, 2003

6