PNX1502E Datasheet, PDF (280/819 Pages) NXP Semiconductors – Connected Media Processor

Philips Semiconductors
Volume 1 of 1
PNX15xx Series
Chapter 8: General Purpose Input Output Pins
IROUT
In the 33% and 66% duty-cycle cases FREQ_DIV must be programmed such that the
resulting frequency is 3 times the actual sub-carrier frequency, i.e the minimum pulse
width (high or low) is programmed. Similarly, in the 50% duty-cycle case FREQ_DIV
must be programmed such that the resulting frequency is 2 times the actual sub-
carrier frequency.
33%
50%
66%
Programmed Freq.
Programmed Freq.
Programmed Freq.
Actual Sub-carrier Freq.
Actual Sub-carrier Freq.
Figure 11: Examples of Duty Cycles for Ir TX Signals
Actual Sub-carrier Freq.
3.2 Spike Filtering
When signal sampling at a programmed frequency a filtering feature is available in
the GPIO module which filters out spikes which may occur on a Ir RX signal. This
feature is enabled by programming the EN_IR_FILTER and IR_FILTER registers. The
IR_FILTER value represents the spike filter pulse width, i.e all pulses less than the
IR_FILTER pulse width are considered spikes and not passed through to the signal
monitoring control.
12NC 9397 750 14321
Product data sheet
Rev. 2 — 1 December 2004
© Koninklijke Philips Electronics N.V. 2002-2003-2004. All rights reserved.
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