Using A Custom Flow With The Application Layer; Custom Flow With Application Layer Example; Roms And Registers - Analog Devices ADAV4601 System Design Document

USING A CUSTOM FLOW WITH THE APPLICATION LAYER

We strongly recommend this approach. The advantage of using the Application Layer is that it automatically takes
care of safeloading. It dramatically reduces the amount of I
and simplifying microcontroller code.

Custom Flow with Application Layer Example

A general 2 nd order low pass filter will have a number of filter cut off frequencies and an address defined by the user
in the Application Layer Software. In order to change the cut off frequency simply write to address of the register
and change it to one of the pre-defined cut offs. For this example assume the address is 0x1000 and a cut off of
2kHz is assigned to a value of 0xF, then write required to change the filter cut off is
This only requires one I 2 C write compared to the previous example which took eleven I

ROMS and Registers

When the ADAV4601 is configured for use with the Application Layer it contains four ROMS: program, instruction,
parameter, and LUT. All can be stored externally on an EEPROM and can be loaded after power-up.
Program ROM
Program ROM is 42-bits wide and occupies Address 0x1400 to Address 0x1FFF. This is where the audio flow
generated in SigmaStudio is stored.
Instruction ROM
Instruction ROM is 33-bits wide and occupies Address 0x3000 to Address 0x327F. This is where the application
layer register map is stored.
Parameter ROM
Parameter ROM is 28-bits wide and occupies Address 0x1000 to Address 0x13FF. Default parameters for custom
flow are stored here.
LUT ROM
LUT ROM is 28-bits wide and occupies Address 0x4000 to Address 0x57FF. This contains the remaining
predefined parameters for the custom flow.
ADAV4601 System Design Document
Rev.1 August 2009
2
C writes to the part freeing up the I
Design custom flow in
SigmaStudio
Link, Compile and generate
params.params file
Using params.params file
and Application Layer
Creation Software generate
ROMs and Register Map
to control the custom
flow as desired
Store ROMs on an external
EPROM for download to the
ADAV4601
Figure 37. Using a Custom Flow with the Application Layer
34 1000 000F
Analog Devices
2
C bus in your system
2 C writes.
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