TB2110FN View Datasheet(PDF) - Toshiba
Part Name
Description
Manufacturer
TB2110FN Datasheet PDF : 19 Pages
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TB2110FN
○ General-purpose counter
The general-purpose counter is used to count frequencies such as the FM / AM band IF frequency to detect the
auto stop signal during auto search tuning.
For this frequency counting, the general-purpose counter uses a frequency measurement (IF-AM, IF-FM input)
method to count the number of pulses input to the counter during a certain duration of time (gate time).
1. General-purpose counter control bits
(1) G0, G1 bits…These bits choose the general-purpose counter’s gate time.
G0 G1 Gate Time
0
0
1 ms
1
0
4 ms
0
1
16 ms
1
1
64 ms
(2) Start bit…Each time the start bit is set to 1, measurement is restarted after resetting the
general-purpose counter.
(3) M8, M9 bits…These bits choose the general-purpose counter’s measurement mode and input pin.
M8 M9
Pin
Selection
Input Frequency
Range
Remarks
0
1
IF-AM
0.3~1.0MHz
Direct input to IF counter
1
0
IF-FM
8~16MHz
IF frequency divided by 2 input to IF counter
(Note) In the IF-FM mode, the general-purpose counter (20 bit binary counter) is preceded by an additionally
inserted 1 / 2 prescaler. Therefore, the input signal from IF-FM is divided by 2 before being fed into the
general-purpose counter.
2. General-purpose counter data output bits (f0~f19)
(1) General-purpose counter count data bits (f0~f19)
The resulting count of the general-purpose counter can be read in binary from the output registers f0
through f19.
(2) General-purpose counter operation detect bits
Over…General-purpose counter
“1” General-purpose counter is in overflow condition.
overflow bit
“0” General-purpose counter data is valid.
Busy…General-purpose counter
operation monitor
“1” General-purpose counter is counting.
“0” General-purpose counter has finished counting.
(Note) When using the general-purpose counter, check to see that the busy bit is 0 (finished counting) and
that the over bit is 0 (valid data) before you reference the contents of the general-purpose counter data
bits (f0~f19).
13
2002-10-30
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