
Continued from preceding page.
DO Output Format (serial data output)
The LC7218 includes a 28-bit internal shift register that can be used to output the following data from DO: the IN0 and
IN1 input port states, the general-purpose counter (20-bit binary counter) and the unlock detection circuit state.
The contents of the shift register is latched at the point that serial data output mode is selected.
No. 4758-9/16
LC7218, 7218M, 7218JM
No.
Control block/data
Description
Related data
(5)
(6)
(7)
(8)
(9)
(10)
(11)
Divider selection data
DV
Sensitivity selection
data
SP
General-purpose
counter input pin
selection data
SC
General-purpose
counter
frequency/period mode
switching data
SF
General-purpose
counter count time
selection data
GT
Time base output
control data
TB
LSI test mode control
data
T
0
, T
1
 DV selects the local oscillator input pin. (FMIN or AMIN)
 SP switches the input frequency range when AMIN is selected.
*
 don’t care
 SC selects the input pin (HCTR or LCTR) for the general-purpose counter.
 SF selects the measurement type (frequency or period) when LCTR is selected.
When HCTR is selected, SF is ignored and the LC7218 operates in frequency measurement 
mode.
*
 don’t care
 GT selects the measurement time in frequency measurement mode and the number of periods 
in period measurement mode.
GT = 0: 60 ms/one period
GT = 1: 120 ms/two periods
(frequency measurement/period measurement)
 When TB is set to 1 an 8 Hz 40% duty clock time base signal is output from OUT0. O
0
bit is 
ignored in this mode.
 T
0
and T
1
switch the LSI between test and normal operating modes. The test modes and have 
no user related functions. Both T
0
and T
1
must always be set to 0.
Be sure to set both T
0
and T
1
to 0 after power is applied.
CTEN
GT
CTEN
SC
SF
O
0
DV
SP
Input pin
Input frequency range (MHz)
1
*
FMIN
10 to 130
0
1
AMIN
2 to 40
0
0
AMIN
0.5 to 10
DV
SP
Input pin
Measurement type
1
*
HCTR
Frequency measurement (sine wave)
0
1
LCTR
Frequency measurement (sine wave)
0
0
LCTR
Period measurement (pulse waveform)
No.
Data
Description
(1)
Input port data 
I
0
and I
1
General-purpose 
counter binary data 
C
19
to C
0
 The values of the IN0 and IN1 input ports are latched into I
0
and I
1
.
I
0
←
 IN
0
, I
1
←
 IN
1
 The C
19
to C
0
data is latched from value of the general-purpose 20-bit binary counter.
C
19
←
 20-bit binary counter MSB
C
0
→
 20-bit binary counter LSB
 The UL3 to UL0 data is latched from the unlock detection circuit.
UL0: 1.11
UL1: 2.22
These bits are set to 1 if a phase difference in excess of these times (in μs) was detected. 
UL2: 3.33
(for a 7.2 MHz crystal)
UL3: 0.55
(2)
PLL unlock state data 
UL3 to UL0
(3)