Hitachi H8/3937 Series Hardware Manual page 355

Table of Contents

Advertisement

COD: Clock Output Disable. When this bit is clear, a 38.4 kHz or 40 kHz (depending on the
values of IDE and DFC) signal will be output on the CLKOUT pin. When this bit is set, the
CLKOUT pin will be driven low. Note that setting and clearing this bit can cause pulses on the
CLKOUT pin that are less than one half the clock period. Also note that when the clock output is
enabled and not set for intermittent operation (see ICO in this packet), the CLKOUT pin will
always output the clock signal even when the FLEX decoder is in reset (as long as the FLEX
decoder oscillator is seeing clocks). Further note that when the FLEX decoder is used in internal
demodulator mode (i.e. uses a 160 kHz oscillator), the CLKOUT pin will be 80 kHz from reset
until the time the IDE bit is set. This is because the FLEX decoder defaults to external
demodulator mode at reset. (value after reset=0)
MTE: Minute Timer Enable. When this bit is set, a Status Packet will be sent at one minute
intervals with the MT (minute time-out) bit in the Status Packet set. When this bit is clear, the
internal one-minute timer stops counting. The internal one-minute timer is reset when this bit is
changed from 0 to 1 or when the MTC (minute timer clear) bit in the Control Packet is set. Note
that the minute timer will not be accurate using a 160 kHz oscillator until the IDE bit is set. (value
after reset=0)
LBP: Low Battery Polarity. This bit defines the polarity of the FLEX decoder's LOBAT pin. The
LB bit in the Status Packet is initialized to the inverse value of this bit when the FLEX decoder is
turned on (by setting the ON bit in the Control Packet). When the FLEX decoder is turned on, the
first low battery update in the Status Packet will be sent to the host when a low battery condition is
detected on the LOBAT pin. Setting this bit means that a high on the LOBAT pin indicates a low
voltage condition. (value after reset=0)
ICO: Intermittent Clock Out. When this bit is clear and COD is clear, a 38.4 kHz or 40 kHz
(depending on the values of IDE and DFC) signal will be output on the CLKOUT pin. When this
bit is set and COD is clear, the clock will only be output on the CLKOUT pin while the receiver is
not in the Off state. The clock will be output for a few cycles before the receiver transitions from
the off state and for a few cycles after the receiver transitions to the off state (this is to insure that
the receiver receives enough clocks to detect and process the changes to and from the Off state).
The CLKOUT pin will be driven low when it is not driving a clock. Note that when the clock is
automatically enabled and disabled (i.e. when ICO is set), the CLKOUT signal transitions will be
clean (i.e. no pulses less than half the clock period) when it transitions between no clock and
clocked output. This bit has no effect when COD is set. (value after reset=0)
343

Advertisement

Table of Contents
loading

Table of Contents