MX803ALH Ver la hoja de datos (PDF) - MX-COM Inc
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MX803ALH Datasheet PDF : 26 Pages
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Audio Signaling Processor
15
MX803A PRELIMINARY INFORMATION
5.2.5.2 Mid Band Measurement
SIN - MID Band
In the measurement period of 18.250ms, there are N cycles
at 2SIN and R clock cycles at 28.000kHz.
N
R
+
= 18.250ms
2SIN
28000
from which SIN
=
14000 x N
(511 - R)
N and R - High Band
The measurement period = 18.250ms.
Clock Frequency = 28.000kHz
The measured frequency = 2SINHz
In the measurement period there are:
2SIN x 18.250 x 10-3 cycles
NMID is the lower integer value of the decimal number:
N = INT (18.250 x 10-3 x 2SIN )
RMID is the lower integer value of the decimal number:
R = INT (18.250 x 10 -3 - N ) x 28000
2SIN
5.2.5.3 Extended Band Measurement
SIN - Extended Band
In the measurement period of 9.125ms, there are N cycles
at 2SIN and R clock cycles at 56.000kHz.
N + R = 9.125ms
2SIN
56000
28000 x N
from which SIN = (511 - R)
N and R - High Band
The measurement period = 9.125ms.
Clock Frequency = 56.000kHz
The measured frequency = 2SINHz
In the measurement period there are:
2SIN x 9.125 x 10-3 cycles
NEXTENDED is the lower integer value of the decimal number:
N = INT (9.125 x 10-3 x 2SIN )
REXTENDED is the lower integer value of the decimal number:
R = INT (9.125 x 10 - 3 - N ) x 56000
2SIN
5.2.6 Write to RX Notone Timer Register
A/C 33H, followed by 1 byte of Command Data
5.2.6.1 Operation of the RX Notone Timer
A NOTONE period is that period when no signal or a consistently bad quality signal is received. The NOTONE Timer is
employed to indicate to the µC that a NOTONE situation has existed for a predetermined period.
The NOTONE Timer period is “primed” by writing to the NOTONE Timer Register (33H) using the instructions and
information (1 data byte) given in Table 6. This timer register can be written-to and set in any mode of the MX803A
except “Notone Timer Powersave.” Priming the timer sets the timing period; this period will not be allowed to start until at
least one frequency (tone) measurement has been successfully completed.
The NOTONE Timer is a one-shot timer that is 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 this timer period, the NOTONE Timer Period Expired bit in the Status Register and an Interrupt are set.
Upon detection of the Interrupt, the Status Register should be read by the µC to ascertain the source of the Interrupt.
© 1996 MX•COM, INC.
Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054
Doc. # 20480122.003
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