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No. 5157-9/16
LC72336, 72338
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Pin No.
Symbol
I/O
I/O type
Function
70
69
68
67
66
65
HCTR
HOLD
PH0/ADI0
PH1/ADI1
PH2/ADI2
PH3/ADI3
I
I
I
CMOS amplifier
input
CMOS input
CMOS input
Analog input
Shared-function universal counter input and general-purpose input port
The IOS instruction (Pn = 3, b3) is used to switch this pin between its universal counter
and general-purpose input port functions.
When used for frequency measurement:
Select the universal counter function with an IOS instruction (Pn = 3, b2 = 0).
Set HCTR frequency measurement mode with a UCS instruction (b3 = 0, b2 = 0). After
selecting the measurement time, start the counter with a UCC instruction.
The CNTEND flag will be set when the count completes.
Since this circuit operates as an AC amplifier in this mode, the input must be capacitor
coupled.
When used as a general-purpose input port:
Set the general-purpose input port function with an IOS instruction (Pn = 3, b2 = 1).
Use the INR (b1) internal register (address 0EH) input instruction to read in the input
data.
Input is disabled in clock stop mode. (The input pin is pulled down.)
The universal counter function is selected after a power-on reset.
Controls the PLL circuit and clock stop mode.
When this pin is set low in the hold enabled state, FMIN and AMIN pin input is disabled
and the EO pin goes to the high-impedance state.
To switch to clock stop mode, set the HOLDEN flag, set this pin low, and execute a
CKSTP instruction.
Set this pin high to clear clock stop mode.
Shared-function general-purpose input and A/D converter input port
The IOS instruction (Pn = 7) is used to switch these pins between the general-purpose
and A/D converter input port functions.
When used as a general-purpose input port:
Set the general-purpose input port function (in bit units) with the IOS instruction
(Pn = 7).
When used for A/D converter input:
Set the A/D converter input port function with an IOS instruction (Pn = 7).
Specify the pin to convert with an IOS instruction (Pn = 1).
Start the conversion with a UCC instruction (b2).
The ADCE flag is set when the conversion has completed.
Note: Since input is disabled, low will always be returned if an input instruction (the IN
instruction) is executed for a port specified for A/D converter input. (In other
words, the port must be set to the general-purpose input function before the input
instruction is executed.)
Input is disabled in clock stop mode.
The general-purpose input function is selected after a power-on reset.