Operation
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4
4.12.2 Initialization-Specific Commands
To make power-up initialization as flexible as possible there are a few commands that are only available during
initialization. These commands are listed below:
The command
Update
is used to activate buffered commands that would otherwise be made active (updated) using
an SPI header command.
The command
InitializationDelay
takes an argument which specifies a delay during stored command initialization
processing. This command is useful in the case that the user wants Atlas to be ready for operation only when other
hardware in the overall system is powered up.
4.13 Non-Volatile (NVRAM) Storage
A primary purpose of the NVRAM is to allow Atlas initialization information to be stored so that upon power up it
can be automatically loaded rather than requiring an external controller to perform this function. In addition however
the NVRAM can be used for other functions such as labeling the stored initialization sequence, or for general purpose
user-defined storage.
All data stored in the Atlas NVRAM utlizes a data format known as PMD Structured data Storage Format (PSF). Users
who rely only on PMD’s Pro-Motion software package to communicate with Atlas and store and retrieve initialization
parameters may not need to concern themselves with the details of PSF. Users who want to address the NVRAM from
their own software, or who want to create their own user-defined storage on the Atlas NVRAM will utilize the PSF
format details provided in the subsequent sections.
4.13.1 PMD Structured Data Format
Figure 4-15:
High-Level
Format of a
PSF (PMD
Structured
Data Format)
Memory Space
PSF (PMD Structured data Format) is a general purpose data storage format designed for use with non-volatile storage
memory such as provided by Atlas Digital Amplifiers. PSF provides a method to store and label initialization
information used by the Atlas during startup, as well as to allow user-defined storage in NVRAM.
shows the overall format of a PSF-managed memory area. The PSF memory space begins with a 4-word
start sequence and a 4-word user programmable sequence. Each word is 16 bits in size, as are future references to
words in the following sections unless otherwise noted. The start sequence must contain, in order, the values 0x0, 0x0,
Atlas® Digital Amplifier Complete Technical Reference
PSF
Start Sequence
Word 4
Word 3
Word 2
Word 1
Word 8
Word 7
Word 6
Word 5
0x0
0x1
0x0
0x0
Segment 1
Segment 2
Segment N...
PSF
Segment
Storage Area
PSF
User Sequence
