Cirrus Logic CS49300, Reference Design, Page: 9 / 51

9
2.3.3 Memory Options
There are many available applications that can run
on the CS49300 family DSP. DSP applications re-
quire a 32k-byte page in an external ROM, Flash,
or other non-volatile storage. Some applications,
called Internal Boot Assisted (IBA) codes, consist
of a few hundred bytes of download firmware.
When using IBA codes ONLY, the external Flash
or ROM may be omitted from the design IF AND
ONLY IF the IBA codes are stored in the host mi-
crocontroller’s available non-volatile memory. In
these applications, U24 and C132 may be omitted.
For a full AAC 5.1 discrete channels of output, ex-
ternal SRAM must be used. For all other applica-
tions, the SRAM U16 and support component
C133 may be omitted. Other options exist for AAC
multichannel, including a stereo downmixed AAC
output following by Dolby ProLogic II processor,
which generates 5.1 channels of output.
For a full list of codes (including IBA codes) and
their requirements, please contact your local Cirrus
Field Applications Engineer.
2.4 Revision A Errata
The revision A CRD42528 requires the following
modification to the mute circuitry. The mute signal
as shown in Figure 2 should be modified as shown
in Figure 3 .
Figure 2. Mute Control Rev A
Figure 3. Mute Control - Corrected