Arm Enterprises IM-AD1 manual Therefore, with a 0.1Ω sense resistor fitted

Page 33

Hardware Reference

The current limit is set by the reference voltage and sense resistor according to the equation:

Ipeak =

Vref

Rsense

Therefore, with a 0.1Ω sense resistor fitted:

Ipeak = 0.15 x 10 = 1.5A

The reference voltage, and therefore the current limit, can be adjusted by altering the values of the divider resistors. Although the DC current switching limit of L298 is 2A, due to the power dissipation limit of the device and the heatsink, the maximum load current for each stepper winding is 1.5A. The L298 can switch drive voltages up to 46V.

Warning

The L298 devices, U24 and U26, and their heatsinks are very hot when high load currents are used.

3.5.2Stepper motor interface signal summary

Table 3-6 shows the assignment of the stepper motor interface signals to the logic module signals on the EXPB connector.

 

 

Table 3-6 Stepper motor interface signals

 

 

 

Signal

EXPB

Description

connector

 

 

 

 

 

STEP1_ENA

F0

Enable signal for STEP1_O1 and STEP1_O2

 

 

 

STEP1_ENB

F1

Enable signal for STEP1_O3 and STEP1_O4

 

 

 

STEP1_PH1

F2

Step1 phase 1 drive signal

 

 

 

STEP1_PH2

F3

Step1 phase 2 drive signal

 

 

 

STEP1_PH3

F4

Step1 phase 3 drive signal

 

 

 

STEP1_PH4

F5

Step1 phase 4 drive signal

 

 

 

STEP2_ENA

F6

Enable signal for STEP2_O1 and STEP2_O2

 

 

 

STEP2_ENB

F7

Enable signal for STEP2_O3 and STEP2_O4

ARM DUI 0163B

Copyright © 2001-2003. All rights reserved.

3-9

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Contents Integrator/IM-AD1 User Guide Integrator/IM-AD1Conformance Notices Copyright 2001-2003. All rights reserved Chapter Introduction Integrator/IM-AD1 User GuideAppendix a Signal Descriptions Preface Using this book About this bookIntended audience Typographical conventions Further readingARM publications Third-party documents Feedback Feedback on this documentFeedback on the Integrator/IM-AD1 Xii Introduction ARM DUI 0163B About the Integrator/IM-AD1Integrator/IM-AD1 layout Features Interface module features and architectureArchitecture Integrator/IM-AD1 block diagramLinks and LEDs Config LEDCare of modules Introduction Copyright 2001-2003. All rights reserved Getting Started Assembled Integrator development system Fitting the interface moduleSwitch 2 Closed Switch 3 Open Switch 4 Open Setting up the logic moduleRunning the test software Hardware Reference Hardware Reference Connector Serial interface signal assignment Signal nameUart interface DescriptionSerial connector signal assignment Pin J18 Type Description Serial connector pinoutSPI SPI signals SignalPWM interface PWM interface signals SignalPWM connector signals Pin J14 J10 Description Shows the signal assignmentFunctional description Stepper motor interfaceTherefore, with a 0.1Ω sense resistor fitted Stepper motor interface signal summaryStepper motor interface signals Stepper motor connectorsVSS Stepper motor connector signals Pin J19 J23 DescriptionGpio Gpio connectors J16 and J17Hardware Reference Can interface U13Buffer Can interface signal assignment Signal IMBBANK28 IMBBANK29IMBBANK30 GND Can connector signal assignments Pin10 ADC and DAC interface architecture ADC and DAC interfacesIMABANK49 IMABANK48IMABANK50 IMABANK5111shows the pinout of the ADC interface connector J1 12 shows the pinout of the DAC interface connector J2 Hardware Reference Copyright 2001-2003. All rights reserved Reference Design Example About the design example About PrimeCellsExample architecture File Description Vhdl file descriptionsExample memory map Integrator system memory map Address assignment of logic modulesIntegrator/IM-AD1 memory map Logic module addresses Position Bits StackIntegrator/IM-AD1 memory map Device Address Gpioa StepperbGpiob SsramExample APB register peripheral Logic module registersOffset address Name Type Function Oscillator divisor registers LMOSCx registers Bits Name Access Function RDWVDW Oscillator lock register Bits Name Access FunctionUser LEDs control register Push button interrupt registerSwitches register Uart SPICS2 SPI chip select registerSPICS1 SPICS0Synchronous serial port PWM controller Stepper motor peripheral Offset Name Access Function AddressCont CountStepper x control register Docount SinglestepDIR Stepx speed register Stepx count registerAddress offset Name Access Size Function Read data output pinsData output set register Read data input registerGpio direction control 1 bit Data directionSsram interface Interrupt sources Vectored interrupt controllerInterrupt Interrupt source Source number CAN1Reference Design Example Canreset Can reset control registerCan controller interface CANxBase16 ADC and DAC interface registers ADC and DAC interfaceAdcstatus ADC2BUSYPeripheral information block 18 PIB entry formatBits Name Function Signal Descriptions Expa Pin label Signal Description Table A-1 AHB signal assignmentExpb Pin label Name Description Table A-2 Expb signal descriptionExpim Table A-3 Expim signal descriptions LabelLM-EP20K1000E Description Figure A-4 J7 pin locations Logic analyzer connectorCLK1 Table A-4 J7 connector pinout Signal PinMulti-ICE Jtag Figure A-5 Multi-ICE connector pinoutMechanical Specification Mechanical information Figure B-1 Board dimensions top viewFigure B-2 Bottom board dimensions viewed from top side Connector reference DB9DUALDB9STRAIGHT FCI Multi-ICE GlossarySynchronous Serial Port ADC Can IndexDAC GpioExpa A-2 Gpiodataclr Gpiodatain Gpiodataout Gpiodataset GpiodirnLmleds Lmlock LMOSC1