ADSP-2126x SHARC Processor Hardware Reference
15-15
System Design
reduce the effect of ringing on processor input signals with fast edges,
because the amount of hysteresis that can be used on a CMOS chip is too
small to make a difference. The small amount of hysteresis allowed is due
to restrictions on the tolerance of the VIL and VIH TTL input levels
under worst-case conditions.
Designing for High Frequency Operation
Because the processor can operate at very fast clock frequencies, signal
integrity and noise problems must be considered for circuit board design
and layout. The following sections discuss these topics and suggest various
techniques to use when designing and debugging processor systems.
All synchronous behavior is specified to
CLKIN
. System designers are
encouraged to clock synchronous peripherals with this same clock source
(or a different low-skew output from the same clock driver).
Clock Specifications and Jitter
The clock signal must be free of ringing and jitter. Clock jitter can easily
be introduced into a system where more than one clock frequency exists.
Figure 15-4. Input Pin Hysteresis
GND
V
IL
V
IH
V
DDEXT
V
T
V
T-
V
T+
ENABLES VT-
ENABLES VT+
Содержание ADSP-21261 SHARC
Страница 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Страница 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Страница 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Страница 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Страница 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...