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Preface
The LH79524 and LH79525 are fully-integrated 16/32-bit SoCs based on a 32-bit
ARM720T core. This User's Guide is the principal technical reference for these devices.
This document assumes the reader is familiar with ARM720T programming. For more
information on programming the ARM720T core, see the library of methods and down-
loads available from ARM Ltd., at http://www.arm.com.
For an abridged version of this User's Guide, consult the LH79524/LH79525 Data Sheet
and the single page Product Brief. For details, contact a SHARP representative or see the
SHARP Microelectronics of the Americas website (http://www.sharpsma.com).
Application Notes and further information on connecting, programming and implementing
the LH79524/LH79525, along with suggestions for companion parts, can be found on
SHARP's website (http://www.sharpsma.com).
IMPORTANT: The following sections contain important design information about the LH79524/LH79525.
Conventions and Terms
For information on specific terms and acronyms see the Glossary in this User's Guide.
Unconnected (Floating) Inputs
Many applications employing the LH79524/LH79525 require extremely low standby and
operating current consumption, especially in battery operated devices. To achieve mini-
mum current, unused inputs must never be left floating (unconnected). Each input must be
pulled up or pulled down with a 33 kΩ resistor (or smaller). In addition to terminating input
pins, this also allows the designer to specify the reset state of input pins by selecting pull
up (logical 1 at reset) or pull down (logical 0 at reset) resistors.
Multiplexed Pins
The LH79524 is manufactured in a CABGA package with 208 pins. The LH79525 is man-
ufactured in a LQFP package with 176 pins. Some pins have only one function, but others
are multiplexed and may carry as many as three functions. Designers must be aware that
multiplexed pins cannot simultaneously support more than one function; a choice is
required prior to designing the SoC into an application.
Please take a moment to read the 'Conventions and Terms' section in its entirety.
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