ADSP-214xx SHARC Processor Hardware Reference
16-23
Peripheral Timers
2. The
PRDCNT
bit determines when the
IRQ
status bit (if enabled) is
set.
• If (
PRDCNT
== 1),
IRQ
is set when the period expires and the
value is captured.
• If (
PRDCNT
== 0),
IRQ
is set when the width expires and the
value is captured.
3. Valid period and width values are set in their respective registers
when
IRQ
is set.
The period and width values are measured with respect to
PCLK
.
This makes this mode coherent with the PWM_OUT mode, where
the output waveforms have a period of 2 x period and a width of 2
x width.
Note that the first period value will not have been measured when
the first width is measured, so it is not valid. The timer sets and
returns a period value of zero in this case. When the period expires,
the period value is placed into the period register. When
IRQ
is
sensed, read the status and perform the appropriate “write-one” to
clear.
EXT_CLK Mode
Use the following procedure to configure and run the timer in EXT_CLK
out mode.
1. Reset the
TIMEN
bit and set the configuration mode to 11 to select
EXT_CLK operation.
This configures the
TIMERx_I
pin as an input pin regardless of the
setting of the
PULSE
bit. Note that the timer always samples the ris-
ing edge in this mode. The period register is WO and the width
register is unused in this mode.
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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...