GPLB30B

© Generalplus Technology Inc.

Proprietary & Confidential

7

Apr. 16, 2009

Version: 1.1

The following figure is the GPLB30B state diagram:

HALT

OPERATING

STANDBY

CPU OFF,

32768 oscillator OFF

Wake-up or user reset

GPLB30B State Diagram

g.

The LCD driver in GPLB30B

upports 1/16 duty and 1/5 bias.

D.

The VLCD is adjustable from 2.98V to 5.75V

ith 27 levels.

etector will generate a system reset if power supply voltage

6.4. LCD Controller/Driver

The

GPLB30B

contains

a

640-dot

LCD

controller/driver.

Programmer is able to define the LCD configuration by setting the

LCD Control Register. Once the LCD configuration is completed,

the desired pattern can be displayed by filling the LCD buffer with

proper data.

The LCD driver can also operate during sleep by

keeping 32768Hz oscillator runnin

s

6.5. LCD Voltage Generator

The GPLB30B offers a voltage regulator and a charge-pumping

circuit.

The voltage regulator supplies the charge-pumping circuit

a reference voltage to generate VLCD.

Users can get the

desired VLCD by changing the output reference voltage (writing to

register) of the voltage regulator.

Enabling the voltage regulator

and charge-pumping circuit gets a stable VLCD that will not be

affected by VD

w

6.6. Low Voltage Reset

The GPLB30B provides a low voltage reset function.

The voltage

drops below 2.1V.

d

6.7. Watchdog Timer (WDT)

An on-chip watchdog timer is also available in the GPLB30B.

The WDT is designed to recover the system from abnormal

operation.

In some cases, if WDT is not cleared for one second,

the WDT will generate a system reset to restart system.

If WDT

is enabled, the WDT should be cleared through software

programming every 0.5 seconds to avoid accidental reset.

Note that the WDT only works when 32768Hz clock is activated.

6.8. Mask Options

6.8.1. 32768 oscillator

─ X’TAL32K

─ Rosc32K

6.8.2. Watchdog timer

─ Enable

─ Disable

6.8.3. PC[0:7]/SEG[39:32]

Each port/segment can be optioned as I/O or LCD segment

individually.

6.8.4. Rosc32k select

1). Built in RC

2). Built in C External R

1). Built in RC

2). Built in C External R

6.8.6. Low voltage reset

1). Disable

2). Enable