1FEATURES

2• KEY FEATURES

– Internal RC Oscillator, No External Clock

Required

– Internal PWM Clock Generation, No

External Clock Required

– External Reset for System Control

– Programmable I2C-compatible ACCESS.bus

Address (Default 0x88)

– Support for Keypad Matrices of up to of 8 x

12 Keys, Plus 8 Special Function (SF) Keys,

for a Full 104 Key Support

– I2C-compatible ACCESS.bus Slave Interface

at 100 kHz (Standard-Mode) and 400 kHz

(Fast-Mode)

– Three Host-programmable PWM Outputs

for Smooth LED Brightness Modulation

– Supports General-purpose I/O Expansion

on Pins Not Otherwise Used for Keypad or

PWM Output

– 15 byte Key Event Buffer

– Multiple Key Event Storage

– Key Events, Errors, and Dedicated

Hardware Interrupts Request Host Service

by Asserting an IRQ Output

– Automatic HALT Mode for Low Power

Operation

– Wake-up from HALT Mode on Any Interface

(Rising Edge, Falling Edge or Pulse)

– Three PWM Outputs with Dedicated Script

Buffer for up to 32 Commands

– Register-based Command Interpreter with

Auto Increment Address

• HOST-CONTROLLED FEATURES

– Reset Input for System Control

– PWM Scripting for Three PWM Outputs

– Period of Inactivity that Triggers Entry into

HALT Mode

– Debounce Time for Reliable Key Event

Polling

– Configuration of General Purpose I/O Ports

– Various Initialization Options (Keypad Size,

etc.)

• KEY DEVICE FEATURES

– 1.8V ± 10% Single-supply Operation

– On-chip Power-on Reset (POR)

– Watchdog Timer

– −40°C to +85°C Temperature Range

– 25-pin DSBGA Package

APPLICATIONS:

• Cordless Phones

• Smart Handheld Devices

• Keyboard Applications

DESCRIPTION

The LM8328 GenI/O - Expander and Keypad

Controller is a dedicated device to unburden a host

processor from scanning a matrix-addressed keypad

and to provide flexible and general purpose, host

programmable input/output functions. Three

independent PWM timer outputs are provided for

dynamic LED brightness modulation.

It communicates with a host processor through an

I2C-compatible ACCESS.bus serial interface. It can communicate in Standard (100 kHz) - and Fast-Mode

400 kHz) in slave Mode only.

All available input/output pins can alternately be used

as an input or an output in a keypad matrix or as a

host programmable general purpose input or output.

Any pin programmed as an input can also sense

hardware interrupts. The interrupt polarity (“high to

low” or “low to high” transition) is thereby

programmable.

The LM8328 follows a predefined register based set

of commands. Upon start-up (power - on) a

configuration file must be sent from the host to setup

the hardware of the device.