CS493253-CL Cirrus Logic Inc, CS493253-CL Datasheet - Page 59

• Manufacturer Part Number: CS493253-CL
• Description: Multi Standard Audio Decoder 44-Pin PLCC
• Manufacturer: Cirrus Logic Inc

Specifications of CS493253-CL

• Package: 44PLCC
• Operating Temperature: 0 to 70 °C

(from the rising edge of RESET). Note: This time
has been tested using the ac3_493263_13.ld
application code release, however other application
code releases MAY take longer than 200mS as they
have may an increased image size and may take
longer to initialize all of the internal state variables.
It is up to the designer to verify the actual times
required for each application code in their system.
8.3. Decreasing Autoboot Times Using
Instead the host toggling the RESET line while
ABOOT is held low, the host decrease the
Autoboot download time by instead downloading a
special code called “GFABT” (Genesis
Autoboot) which first speeds up the DSP’s core
clock, and then automatically causes the DSP to
Autoboot itself from external ROM.
Basically, the host should perform a normal serial
host boot with one of the GFABT codes (gfabt8.ld,
gfabt6.ld or gfabt4.ld) as described in Section
8.1.1, (with ABOOT held high).
following the download of the GFABT code, the
DSP will start to act the exact same way as if the
Table 11. Reduced Autoboot Times using GFABT8.LD, GFABT6.LD, and GFABT4.LD on a CS493264-CL Rev. G DSP
DS339PP4
Application
Code Name
(8.3 File Name)
Application
Code Name
(Long File
Name)
Code Size on
Disk
Code Size in
Bytes
Sample 1
Sample 2
Sample 3
GFABT Codes (Fast Autoboot)
Open Loop
12.5 MHz
12.4 MHz
11.7 MHz
VCO
ac3_pl~1.ld
ac3_pl2_
493264_
98 ms
99 ms
97 ms
reeq_
08.ld
94 k
24 k
Standard Autoboot Times
Immediately
dts_6d~1.ld
dts_6dot1_
493264_
96 ms
98 ms
96 ms
reeq_
04.ld
94 k
24 k
Fast
host had toggled the RESET line with ABOOT
held low, only now, the code image held in the
external flash or eprom page will now be
downloaded anywhere from 1.5 to 3 times faster
than using Autoboot, depending on the gfabt code
that was first downloaded.
The normal DSP clock divide factor during
Autoboot is 12 (VCO open loop frequency
divider). The gfabt8.ld code changes that divide
factor to 8, the gfabt6.ld code changes it to 6, and
the gfabt4.ld code changes it to 4. Contact your
FAE in order to obtain these gfabt codes.
Some sample data for various autoboot times can
be
ac3_pl2_reeq_493264_08.ld application code. It
shows that the autoboot times after downloading
gfabt8.ld,
approximately 1.5, 2, and 3 times faster than a
standard autoboot. The typical autoboot time listed
in the datasheet of 200 ms will therefore become
135 ms (200ms/1.5), 100ms (200ms/2), and 70ms
(200/3) with gfabt8, 6, and 4, respectively.
eff_49~1.ld
eff_4932xx
_14.ld
48 ms
50 ms
48 ms
47 k
12 k
seen
below
GFABT4.LD
ac3_pl~1.ld
gfabt6.ld,
34 ms
34 ms
32 ms
CS49300 Family DSP
in
GFABT6.LD
ac3_pl~1.ld
and
Table 11
50 ms
50 ms
50 ms
gfabt4.ld
using
GFABT8.LD
ac3_pl~1.ld
65 ms
67 ms
66 ms
the
are
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