comp_b.c

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//*****************************************************************************
//
// comp_b.c - Driver for the comp_b Module.
//
//*****************************************************************************
 
//*****************************************************************************
//
//
//*****************************************************************************
 
#include "inc/hw_memmap.h"
 
#ifdef __MSP430_HAS_COMPB__
#include "comp_b.h"
 
#include <assert.h>
 
bool Comp_B_init(uint16_t baseAddress, Comp_B_initParam *param)
{
    bool retVal = STATUS_SUCCESS;
 
    //Reset COMPB Control 1 & Interrupt Registers for initialization (OFS_CBCTL3
    //is not reset because it controls the input buffers of the analog signals
    //and may cause parasitic effects if an analog signal is still attached and
    //the buffer is re-enabled
    HWREG16(baseAddress + OFS_CBCTL0) &= 0x0000;
    HWREG16(baseAddress + OFS_CBINT)  &= 0x0000;
 
    //Clear reference voltage and reference source
    HWREG16(baseAddress + OFS_CBCTL2) &= ~(CBRS_3 | CBREFL_3);
 
    //Set the Positive Terminal
    if(COMP_B_VREF != param->positiveTerminalInput) {
        //Enable Positive Terminal Input Mux and Set it to the appropriate input
        HWREG16(baseAddress + OFS_CBCTL0) |= CBIPEN + param->positiveTerminalInput;
 
        //Disable the input buffer
        HWREG16(baseAddress + OFS_CBCTL3) |= (1 << param->positiveTerminalInput);
    }
    else {
        //Reset and Set COMPB Control 2 Register
        //Set Vref to go to (+)terminal
        HWREG16(baseAddress + OFS_CBCTL2) &= ~(CBRSEL);
    }
 
    //Set the Negative Terminal
    if (COMP_B_VREF != param->negativeTerminalInput) {
        //Enable Negative Terminal Input Mux and Set it to the appropriate input
        HWREG16(baseAddress + OFS_CBCTL0) |= CBIMEN + (param->negativeTerminalInput << 8);
 
        //Disable the input buffer
        HWREG16(baseAddress + OFS_CBCTL3) |= (1 << param->negativeTerminalInput);
    }
    else {
        //Reset and Set COMPB Control 2 Register
        //Set Vref to go to (-) terminal
        HWREG16(baseAddress + OFS_CBCTL2) |= CBRSEL;
    }
 
    //Reset and Set COMPB Control 1 Register
    HWREG16(baseAddress + OFS_CBCTL1) =
        param->powerModeSelect //Set the power mode
        + param->outputFilterEnableAndDelayLevel //Set the filter enable bit and delay
        + param->invertedOutputPolarity; //Set the polarity of the output
 
    return (retVal);
}
 
void Comp_B_configureReferenceVoltage(uint16_t baseAddress,
    Comp_B_configureReferenceVoltageParam *param)
{
    //Set to VREF0
    HWREG16(baseAddress + OFS_CBCTL1) &= ~(CBMRVS);
 
    //Reset COMPB Control 2 Bits (Except for CBRSEL which is set in Comp_Init())
    HWREG16(baseAddress + OFS_CBCTL2) &= CBRSEL;
 
    //Set Voltage Source (Vcc | Vref, resistor ladder or not)
    if (COMP_B_VREFBASE_VCC == param->supplyVoltageReferenceBase) {
        HWREG16(baseAddress + OFS_CBCTL2) |= CBRS_1; //Vcc with resistor ladder
    }
    else if (param->lowerLimitSupplyVoltageFractionOf32 == 32) {
        //If the lower limit is 32, then the upper limit has to be 32 due to the
        //assertion that upper must be >= to the lower limit. If the numerator is
        //equal to 32, then the equation would be 32/32 == 1, therefore no resistor
        //ladder is needed
        HWREG16(baseAddress + OFS_CBCTL2) |= CBRS_3; //Vref, no resistor ladder
    }
    else {
        HWREG16(baseAddress + OFS_CBCTL2) |= CBRS_2; //Vref with resistor ladder
    }
 
    //Set COMPD Control 2 Register
    HWREG16(baseAddress + OFS_CBCTL2) |=
        param->supplyVoltageReferenceBase //Set Supply Voltage Base
        + ((param->upperLimitSupplyVoltageFractionOf32 - 1) << 8) //Set Supply Voltage Num.
        + (param->lowerLimitSupplyVoltageFractionOf32 - 1);
 
    HWREG16(baseAddress + OFS_CBCTL2) &= ~(CBREFACC);
    HWREG16(baseAddress + OFS_CBCTL2) |= param->referenceAccuracy;
}
 
void Comp_B_enableInterrupt(uint16_t baseAddress,
    uint16_t interruptMask)
{
    //Set the Interrupt enable bit
    HWREG16(baseAddress + OFS_CBINT) |= interruptMask;
}
 
void Comp_B_disableInterrupt(uint16_t baseAddress,
    uint16_t interruptMask)
{
    HWREG16(baseAddress + OFS_CBINT) &= ~(interruptMask);
}
 
void Comp_B_clearInterrupt(uint16_t baseAddress,
    uint16_t interruptFlagMask)
{
    HWREG16(baseAddress + OFS_CBINT) &= ~(interruptFlagMask);
}
 
uint8_t Comp_B_getInterruptStatus(uint16_t baseAddress,
    uint16_t interruptFlagMask)
{
    return(HWREG16(baseAddress + OFS_CBINT) & interruptFlagMask);
}
 
void Comp_B_setInterruptEdgeDirection(uint16_t baseAddress,
    uint16_t edgeDirection)
{
    //Set the edge direction that will trigger an interrupt
    if(COMP_B_RISINGEDGE == edgeDirection) {
        HWREG16(baseAddress + OFS_CBCTL1) &= ~(CBIES);
    }
    else if(COMP_B_FALLINGEDGE == edgeDirection) {
        HWREG16(baseAddress + OFS_CBCTL1) |= CBIES;
    }
}
 
void Comp_B_toggleInterruptEdgeDirection(uint16_t baseAddress)
{
    HWREG16(baseAddress + OFS_CBCTL1) ^= CBIES;
}
 
void Comp_B_enable(uint16_t baseAddress)
{
    HWREG16(baseAddress + OFS_CBCTL1) |= CBON;
}
 
void Comp_B_disable(uint16_t baseAddress)
{
    HWREG16(baseAddress + OFS_CBCTL1) &= ~(CBON);
}
 
void Comp_B_shortInputs(uint16_t baseAddress)
{
    HWREG16(baseAddress + OFS_CBCTL1) |= CBSHORT;
}
 
void Comp_B_unshortInputs(uint16_t baseAddress)
{
    HWREG16(baseAddress + OFS_CBCTL1) &= ~(CBSHORT);
}
 
void Comp_B_disableInputBuffer(uint16_t baseAddress,
    uint8_t inputPort)
{
    HWREG16(baseAddress + OFS_CBCTL3) |= (1 << inputPort);
}
 
void Comp_B_enableInputBuffer(uint16_t baseAddress,
    uint8_t inputPort)
{
    HWREG16(baseAddress + OFS_CBCTL3) &= ~(1 << inputPort);
}
 
void Comp_B_swapIO(uint16_t baseAddress)
{
    HWREG16(baseAddress + OFS_CBCTL1) ^= CBEX;
}
 
uint16_t Comp_B_outputValue(uint16_t baseAddress)
{
    return (HWREG16(baseAddress + OFS_CBCTL1) & CBOUT);
 
}
 
void Comp_B_selectReferenceVoltage(uint16_t baseAddress, uint16_t selectType,
    uint16_t selectVRef)
{
    HWREG16(baseAddress + OFS_CBCTL1) &= ~(CBMRVS | CBMRVL);
    if(selectType == COMP_B_VREF_MANUAL_SELECT) {
        HWREG16(baseAddress + OFS_CBCTL1) |= CBMRVS;
        if(selectVRef == COMP_B_SELECT_VREF1) {
            HWREG16(baseAddress + OFS_CBCTL1) |= CBMRVL;
        }
    }
}
 
 
#endif
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