Modes of Operation
3
Modes of Operation
The LMK03328 can be configured to start-up in one of three modes upon power-on/reset (POR). The
mode of operation and associated control pins determine which on-chip memory type and memory page
settings are used to initialize the active registers to configure the Input, PLL, Output, Device Control, and
Status blocks for full operation:
1.
Soft Pin Modes
(EVM Default) – Loads all registers with one of the 6 page settings in EEPROM. In
the EVM-default EEPROM image, all 6 EEPROM pages have pre-programmed register settings to
demonstrate the various clock configurations in Soft Pin Mode using the default EVM hardware. The
EEPROM settings can be easily re-programmed by the user through the GUI platform.
2.
Hard Pin Modes
– Loads all registers from one of the 64 page settings in ROM. All 64 ROM pages
are “hard-coded” with predefined register settings by TI.
NOTE:
Refer to the ROM page configurations for Hard Pin Mode in the LMK03328 datasheet. Some
ROM page settings may not operate with the default EVM configuration, and modification of
the EVM may be necessary to operate the intended mode. EVM modification areas may
include the crystal (Y1), PRIREF / SECREF input interfaces, OUT / STATUS output
interfaces, and PLL1 / PLL2 loop filter C2 capacitor selection (switches S1 / S2).
3.
Register Default Mode
– Loads all registers from the register default setting. The Register Default
Mode is hard-coded with predefined settings.
NOTE:
Refer to the Register Default Mode in the LMK03328 datasheet. The Register Default Mode
will NOT operate using the on-board 50 MHz crystal (Y1) as the device expects a 25 MHz
reference input. To operate in Register Default Mode using a crystal input, Y1 must be
changed to a 25-MHz, 9-pF crystal (example P/N: TXC 7M25072001).
Once the LMK03328 is start-up in any of these modes, the I2C interface is enabled to provide (optional)
access to all device register for full control of the LMK03328 settings. For convenience, a USB-to-I2C
interface is integrated on-board and can be controlled by the GUI platform.
4
Configuring the EVM
The LMK03328 is a highly-configurable clock generator with multiple power domains and input & output
clock domains. To support a wide range of evaluation use cases, the EVM was designed for maximum
flexibility so it has more functionality than actually needed to implement the clock solution in a typical
system application.
This section describes the jumpers and connectors on the EVM, as well as how to connect, set-up, and
use the LMK03328EVM. When operating the LMK03328EVM, the power supply, clock inputs, and clock
outputs can be connected to the SMA ports shown in
. These SMA ports are labeled in the top
silkscreen layer.
7
SNAU184 – August 2015
LMK03328EVM User’s Guide
Copyright © 2015, Texas Instruments Incorporated
