ADSP-214xx SHARC Processor Hardware Reference
3-129
External Port
3. Execute the desired PLL programming sequence. (
mation, see “PLL Start-Up” on page 22-9.
4. Wait 4096
CLKIN
cycles (
RESETOUT
asserted) which indicates the
PLL has settled to the new frequency.
5. Reprogram the SDRAM registers (
SDRRC
,
SDCTL
) with values appro-
priate to the new
SDCLK
frequency and assure that the
SDPSS
bit is
set.
6. Bring the SDRAM out of self-refresh mode by performing a
dummy read SDRAM access.
7. The SDC now issues the commands
PREA
,
8xREF
and
MRS
to initial-
ize the SDC and the SDRAM to the new frequency.
The SDRAM device is now ready to be accessed.
DDR2 Controller
The following sections are specific to DDR2 SDRAM memory on the
ADSP-2146x processor.
Power-Up Sequence
The following steps are used to power-up the DDR2 device.
1. Ensure the minimum DDR2 clock frequency is stable and at least
125 MHz (according to datasheet).
2. Program the core to DDR2 clock ratio using the
PMCTL
register. For
PLL changes wait at least 4096 core cycles, for output divider
changes at least 15 core clock cycles for effect latency.
3. If a new frequency is desired, put the on-chip DLL into reset using
DLL1-0CTL1
registers.
4. Wait at least 9 core cycles for the DLL to lock to a new frequency.
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Содержание SHARC ADSP-214 Series
Страница 60: ...Contents lx ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
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...
Страница 290: ...Programming Model 4 26 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 296: ...Programming Model 5 6 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
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...