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.