Omega Engineering OME-A8111 manual Timer/Counter

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2.68254 Timer/Counter

The 8254 Programmable timer/counter has 4 registers from Base+0 through Base+3. For detailed programming information about 8254, please refer to Intel‘s “Microsystem Components Handbook”. The block diagram is as below.

Gate

Cin	Cout
	Counter 0

Cin: clock input
Cin: clock input			Counter 1
Cout: clock output			Counter 1
INTCLK: internal clock
INTCLK: internal clock
	Cin		Gate			Cout

			Counter 2
	2M	Cin		Cout
	INTCLK	Cin	Gate	Cout
	INTCLK		Gate

PACER CLK

VCC

10K

Counter0, counter1 and counter2 are all 16 bit counters. Counter 1 and counter 2 cascade as a 32-bit timer. The 32-bit timer is used as a pacer timer.

OME-A-8111 Hardware Manual (ver.1.1, Jul/2003)

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Contents User’sGuide Benelux CanadaMexico Czech RepublicOME-A-8111 Table of Contents Calibration Features General DescriptionAnalog Inputs SpecificationsPower Consumption 3 A/D ConverterDigital I/O DA ConverterInterrupt Channel Product Check List Programmable Timer/CounterApplications Hardware Configuration Board LayoutI/O Base Address Setting Default base address isJumper Setting 1 JP1 D/A Internal Reference Voltage SelectionI/O Register Address Address Read Write8254 Counter 2 A/D Input Buffer Register3 D/A Output Latch Register 4 D/I Input Buffer RegisterClear Interrupt Request 6 A/D Gain Control Register7 A/D Multiplex Control Register 8 A/D Mode Control Register SI2 SI1 SI09 A/D Software Trigger Control Register 10 D/O Output Latch Register Digital I/O CN38254 Timer/Counter CounterA/D Conversion Sec1 A/D conversion flow If switching from one channel to the next secPacer Trigger Mode 2 A/D Conversion Trigger ModesUsing software trigger and polling transfer 3 A/D Transfer ModesD/A Conversion Analog Input Signal Connection Signal ShieldingPin Assignment CN1 Analog input/Analog output/Connect Pin AssignmentCN2 Analog input/Analog output/Connect Pin Assignment CN3 Analog input/Analog output/Connect Pin AssignmentOME-DB-16P Daughter BoardOME-CA-4002 OME-DB-16RCalibration Calibration VR DescriptionD/A Calibration Steps DI/O TestingA/D Calibration Steps WARRANTY/DISCLAIMER Temperature