FX803 Datasheet, PDF (10/17 Pages) Sanyo Semicon Device – DC-DC Converter

Controlling Protocol ......
“Write
to
the
Rx
NOTONE
Timer
Register”
–
A/C
33
H
followed
by
1
byte
of
Command
Data.
Setting
MSB
76 5 4
00 0 0
321 0
000 0
000 1
001 0
001 1
010 0
010 1
011 0
011 1
100 0
100 1
101 0
101 1
110 0
110 1
111 0
111 1
Function/Period
Transmitted Bit 7 First
These 4 bits must be “0”
High/Extended
Band
period (ms) 0
"
20 ±1%
40 "
60 "
80 "
100 "
120 "
140 "
160 "
180 "
200 "
220 "
240 "
260 "
280 "
300 "
Mid
Band
0
40 ±1%
80 "
120 "
160 "
200 "
240 "
280 "
320 "
360 "
400 "
440 "
480 "
520 "
560 "
600 "
Table 6 Rx NOTONE Timer Settings
Operation of the Rx NOTONE Timer
An Rx NOTONE period is that period when no signal or a
consistently bad-quality signal is received.
The Rx NOTONE Timer can be employed to indicate to the
µController that a NOTONE situation has existed for a
predetermined period.
This timer register can be written-to and set in any
mode of the FX803.
The NOTONE Timer period is ‘primed’ by writing to the
NOTONE
Timer
Register
(33 )
H
using
the
settings
given
in
Table 6.
“Priming” sets the timing period; this period can only
start directly after a frequency (tone) measurement
has been successfully completed.
The NOTONE Timer is a one-shot timer being reset only
by successful tone measurements.
If the quality of the received signal drops to an unusable
level the NOTONE Timer will start its run-down.
On completion of the preset period, the NOTONe Timer
Period Expired bit in the Status Register and the Interrupt
(when enabled, Table 2) are set.
Upon detection of the Interrupt, the Status Register
should be read by the µController to ascertain the source
of the Interrupt.
The NOTONe Timer Period Expired bit is cleared:
i By a read of the Status Register or,
ii New NOTONE Timer information or,
iii General Reset command
This timer is set to 00 (0ms) by a General Reset command.
H
The following situations may be encountered by the NOTONE Timer circuitry:
No Signal
The NOTONE Timer can only start its run down on
completion of a valid frequency measurement.
Signal Fades after a Valid Tone Measurement
The timer will start to run down when the signal becomes
unreadable to the device. At the end of the “primed” period
the NOTONe Timer Period Expired bit in the Status Register
and the Interrupt will be set.
No Signal after a Valid Tone Measurement
The timer will start to run down when the last Rx Tone
Measurement complete bit is set. At the end of the
“primed” period the NOTONe Timer Period Expired bit in the
Status Register and the Interrupt will be set.
Signal Appears after the Timer has Started
If the frequency measurement is more than 75% complete
when the timer period expires, neither the NOTONE bit nor
the Interrupt will be set unless that frequency
measurement is subsequently aborted.
10