Z86L70 Datasheet, PDF (26/61 Pages) Zilog, Inc. – IR/Low-Voltage Microcontroller

Z86L70/71/75/C71
IR/Low-Voltage Microcontroller
CTR1 Register Description
Mode. If it is 0, the Counter/Timers are in the transmit
mode, otherwise they are in the demodulation mode.
P36_Out/Demodulator_Input. In Transmit Mode, this bit
defines whether P36 is used as a normal output pin or the
combined output of T8 and T16.
In Demodulation Mode, this bit defines whether the input
signal to the Counter/Timers is from P20 or P31.
T8/T16_Logic/Edge _Detect. In Transmit Mode, this field
defines how the outputs of T8 and T16 are combined
(AND, OR, NOR, NAND).
In Demodulation Mode, this field defines which edge
should be detected by the edge detector.
Transmit_Submode/Glitch Filter. In Transmit Mode, this
field defines whether T8 and T16 are in the "Ping-Pong"
mode or in independent normal operation mode. Setting
this field to "Normal Operation Mode" terminates the "Ping-
Pong Mode" operation. When set to 10, T16 is immediately
forced to a 0. When set to 11, T16 is immediately forced to
a 1.
Zilog
In Demodulation Mode, this field defines the width of the
glitch that should be filtered out.
Initial_T8_Out/Rising_Edge. In Transmit Mode, if 0, the
output of T8 is set to 0 when it starts to count. If 1, the out-
put of T8 is set to 1 when it starts to count. When this bit is
set to 1 or 0, T8_OUT will be set to the opposite state of
this bit. This insures that when the clock is enabled a tran-
sition occurs to the initial state set by CTR1, D1.
In Demodulation Mode, this bit is set to 1 when a rising
edge is detected in the input signal. In order to reset it, a 1
should be written to this location.
Initial_T16 Out/Falling _Edge. In Transmit Mode, if it is 0,
the output of T16 is set to 0 when it starts to count. If it is
1, the output of T16 is set to 1 when it starts to count. This
bit is effective only in Normal or Ping-Pong Mode (CTR1,
D3, D2). When this bit is set, T16_OUT will be set to the
opposite state of this bit. This insures that when the clock
is enabled a transition occurs to the initial state set by
CTR1, D0.
In Demodulation Mode, this bit is set to 1 when a falling
edge is detected in the input signal. In order to reset it, a 1
should be written to this location.
Note: Modifying CTR1, (D1 or D0) while the counters are
enabled will cause un-predictable output from T8/16_OUT.
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PRELIMINARY
DS97LVO0500