Table 9-3 Inverter (Inv) Bit Operation; Inverter (Inv) — Tcsr Bit 8 - Motorola DSP56305 User Manual

9.3.3.5 Inverter (INV) — TCSR Bit 8
The Inverter (INV) bit affects the polarity of the incoming signal on the TIO input signal
and the polarity of the output pulse generated on the TIO output signal. The effects of
the INV bit are summarized in Table 9-3.
TIO Programmed as Input
Mode
INV = 0
0 GPIO signal on
the TIO signal
read directly
1 Counter is
incremented on
the rising edge of
the signal from
the TIO signal
2 Counter is
incremented on
the rising edge of
the signal from
the TIO signal
3 Counter is
incremented on
the rising edge of
the signal from
the TIO signal
4 Width of the high
input pulse is
measured.
5 Period is
measured
between the
rising edges of
the input signal.
MOTOROLA

Table 9-3 Inverter (INV) Bit Operation

INV = 1
GPIO signal on
the TIO signal
inverted
Counter is
incremented on
the falling edge of
the signal from
the TIO signal
Counter is
incremented on
the falling edge of
the signal from
the TIO signal
Counter is
incremented on
the falling edge of
the signal from
the TIO signal
Width of the low
input pulse is
measured.
Period is
measured
between the
falling edges of
the input signal.
DSP56305 User's Manual
TIO Programmed as Output
INV = 0
Bit written to Bit written to GPIO
GPIO put on TIO inverted and
signal directly
on TIO signal
—
TCRx output put TCRx output
on TIO signal inverted and put
directly on TIO signal
—
—
—
Timer/Event Counter
Timer Architecture
INV = 1
put
—
—
—
—
9-13