
ADSP-214xx SHARC Processor Hardware Reference
14-7
Precision Clock Generator
can theoretically run at up to the
PCLK
frequency. However the DAI/DPI
pin buffers limit the speed to
PCLK
/4.
Note that the clock output is always set (as closely as possible) to a 50%
duty cycle. If the clock divisor is even, the duty cycle of the clock output is
exactly 50%. If the clock divisor is odd, then the duty cycle is slightly less
than 50%. The low period of the output clock is one input clock period
more than the high period of the output clock. For higher values of an
odd divisor, the duty cycle is close to 50%.
A PCG clock output cannot be fed to its own input.
Frame Sync
The following sections describe the use of frame syncs in the PCGs.
Frame Sync Output
Each of the four units (A through D) also produces a synchronization sig-
nal for framing serial data. The frame sync outputs are much more flexible
since they need to accommodate the wide variety of serial protocols used
by peripherals.
Frame sync generation from a unit is independently enabled and con-
trolled. Sources for the frame sync generation can be either from the
crystal buffer output,
PCLK
, or an external pin source. There is only one
external source pin for both frame sync and clock output for a unit.
If an external source is selected for both frame sync and clock output for a
unit, then they operate on the same input signal. Apart from enable and
source select control bits, frame sync generation is controlled by a 20-bit
divisor.
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Summary of Contents for SHARC ADSP-214 Series
Page 60: ...Contents lx ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 72: ...Notation Conventions lxxii ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 130: ...Programming Model 2 52 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 264: ...Programming Models 3 134 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 290: ...Programming Model 4 26 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 296: ...Programming Model 5 6 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 396: ...Effect Latency 7 28 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 520: ...Programming Model 10 62 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 616: ...Debug Features 14 22 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 656: ...Programming Model 15 40 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 714: ...Programming Model 19 10 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 1132: ...Register Listing A 306 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 1192: ...Index I 34 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...