Clocking AMI/DDR2
3-6
ADSP-214xx SHARC Processor Hardware Reference
The SDRAM clock ratio settings are independent from the periph-
eral clock (
PCLK
).
To obtain certain higher SDRAM frequencies, the core frequency
may need to be reduced.
Clocking AMI/DDR2
The fundamental timing clock of the external port is DDR2 clock
(
DDR2_CLK
). The AMI/DDR2 controller is capable of running up to core
clock/2 speed (
CCLK
/2) and can run at various frequencies, depending on
the programmed DDR2 clock (
DDR2_CLK
) to core clock (
CCLK
) ratios. For
information processor instruction rates, see the appropriate processor data
sheet.
The DDR2 clock ratio settings are independent from the periph-
eral clock (
PCLK
).
Table 3-2. External Port Clock Frequencies
CCLK:SDCLK
Clock Ratio
CCLK = 400
MHz
CCLK = 333
MHz
CCLK = 266
MHz
CCLK = 200
MHz
1:2.0
N/A
166
133
100
1:2.5
160
133
106
80
1:3.0
133
111
88
67
1:3.5
114
95
76
57
1:4.0
100
83
66
25
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Содержание SHARC ADSP-214 Series
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Страница 72: ...Notation Conventions lxxii ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 130: ...Programming Model 2 52 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 264: ...Programming Models 3 134 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
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Страница 396: ...Effect Latency 7 28 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 520: ...Programming Model 10 62 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 616: ...Debug Features 14 22 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 656: ...Programming Model 15 40 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 714: ...Programming Model 19 10 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1132: ...Register Listing A 306 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1192: ...Index I 34 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...