CS49310 datasheet(61/90 Pages) CIRRUS

61 / 90 page

CS49300 Family DSP

DS339F7

8.3. Decreasing Autoboot Times Using

GFABT Codes (Fast Autoboot)

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

Fast

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).

Immediately

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

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

seen

below

Table 11

using

the

ac3_pl2_reeq_493264_08.ld application code. It

shows that the autoboot times after downloading

gfabt8.ld,

gfabt6.ld,

and

gfabt4.ld

are

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,

and

respectively.

Open Loop

VCO

Standard Autoboot Times

GFABT4.LD

GFABT6.LD

GFABT8.LD

Application

Code Name

(8.3 File Name)

ac3_pl~1.ld

dts_6d~1.ld

eff_49~1.ld

ac3_pl~1.ld

Application

Code Name

(Long File

Name)

ac3_pl2_

reeq_

493264_

08.ld

dts_6dot1_

reeq_

493264_

04.ld

eff_4932xx

_14.ld

Code Size on

Disk

94 k

47 k

Code Size in

Bytes

24 k

12 k

Sample 1

12.5 MHz

98 ms

96 ms

48 ms

34 ms

50 ms

65 ms

Sample 2

12.4 MHz

99 ms

98 ms

50 ms

34 ms

50 ms

67 ms

Sample 3

11.7 MHz

97 ms

96 ms

48 ms

32 ms

50 ms

66 ms

Table 11. Reduced Autoboot Times using GFABT8.LD, GFABT6.LD, and GFABT4.LD on a CS493264-CL

Rev. G DSP

CS49310 数据表(PDF) 61 Page - Cirrus Logic

CS49310 数据表(HTML) 61 Page - Cirrus Logic

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90

数据表下载

链接网址

CS49310 数据表(PDF) 61 Page - Cirrus Logic

CS49310 数据表(HTML) 61 Page - Cirrus Logic

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90

数据表 下载

链接网址

数据表下载