CS493253-CLZ Cirrus Logic Inc, CS493253-CLZ Datasheet - Page 61

• Manufacturer Part Number: CS493253-CLZ
• Description: Audio DSPs IC Multi-Standard Audio Decoder
• Manufacturer: Cirrus Logic Inc

Specifications of CS493253-CLZ

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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
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
DS339F7
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
Table 11. Reduced Autoboot Times using GFABT8.LD, GFABT6.LD, and GFABT4.LD on a CS493264-CL
GFABT Codes (Fast Autoboot)
Open Loop
12.5 MHz
12.4 MHz
11.7 MHz
VCO
ac3_pl~1.ld
ac3_pl2_
493264_
97 ms
98 ms
99 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
Rev. G DSP
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.
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
GFABT4.LD
gfabt6.ld,
below
ac3_pl~1.ld
34 ms
34 ms
32 ms
CS49300 Family DSP
in
The typical autoboot time
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
are
the
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