Other Parts Discussed in Thread: MSP430WARE
Hi experts,
The CCS project uses the following:
C:\ti\msp\MSP430Ware_3_80_11_07\usblib430\MSP430_USB_Software\MSP430_USB_API\examples\HID_humanInterface\Traditional\H8_Keyboard
The MSP430 executes the USBVECINT_PWR_VBUSOff process of UsbIsr.c when it detects a low voltage on the VBUS.
case USBVECINT_PWR_VBUSOff:
PWRVBUSoffHandler();
if (wUsbEventMask & kUSB_VbusOffEvent)
{
bWakeUp = USB_handleVbusOffEvent();
}
The PWRVBUSoffHandler () function called in this process has the following code:
VOID PWRVBUSoffHandler(VOID)
{
volatile unsigned int i;
for (i =0; i < USB_MCLK_FREQ/1000*1/10; i++); // 1ms delay
if (!(USBPWRCTL & USBBGVBV))
{
USBKEYPID = 0x9628; // set KEY and PID to 0x9628 -> access to configuration registers enabled
bEnumerationStatus = 0x00; // device is not enumerated
bFunctionSuspended = FALSE; // device is not suspended
USBCNF = 0; // disable USB module
USBPLLCTL &= ~UPLLEN; // disable PLL
USBPWRCTL &= ~(VBOFFIE + VBOFFIFG + SLDOEN); // disable interrupt VBUSoff
USBKEYPID = 0x9600; // access to configuration registers disabled
}
}
This function disables the USB PLL.
Why does the MSP430 need to disable the USB PLL?
I've read the F5x UG, but I don't know why to disable the PLL, so I'd like to know the reason for this.
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// Generated by MSP USB Descriptor Tool: Tue Feb 03 13:27:36 CST 2015
/*-----------------------------------------------------------------------------+
| Include files |
|-----------------------------------------------------------------------------*/
#include <USB_API/USB_Common/device.h> // Basic Type declarations
#include <USB_API/USB_Common/defMSP430USB.h>
#include "descriptors.h"
#include <USB_API/USB_Common/usb.h> //USB-specific Data Structures
#include <USB_API/USB_Common/UsbIsr.h>
#include <string.h>
#include <USB_API/USB_HID_API/UsbHid.h>
#include <USB_API/USB_HID_API/UsbHidReq.h>
/*----------------------------------------------------------------------------+
| External Variables |
+----------------------------------------------------------------------------*/
extern uint8_t bFunctionSuspended;
extern __no_init tEDB0 __data16 tEndPoint0DescriptorBlock;
extern __no_init tEDB __data16 tInputEndPointDescriptorBlock[];
extern __no_init tEDB __data16 tOutputEndPointDescriptorBlock[];
extern volatile uint8_t bHostAsksUSBData;
extern volatile uint8_t bTransferInProgress;
extern volatile uint8_t bSecondUartTxDataCounter[];
extern volatile uint8_t* pbSecondUartTxData;
extern uint8_t bStatusAction;
extern uint16_t wUsbEventMask;
int16_t CdcToHostFromBuffer(uint8_t);
int16_t CdcToBufferFromHost(uint8_t);
int16_t CdcIsReceiveInProgress(uint8_t);
int16_t HidToHostFromBuffer(uint8_t);
int16_t HidToBufferFromHost(uint8_t);
int16_t HidIsReceiveInProgress(uint8_t);
extern uint16_t wUsbHidEventMask;
int16_t PHDCToHostFromBuffer(uint8_t);
int16_t PHDCToBufferFromHost(uint8_t);
int16_t PHDCIsReceiveInProgress(uint8_t);
uint16_t USB_determineFreq(void);
/*----------------------------------------------------------------------------+
| General Subroutines |
+----------------------------------------------------------------------------*/
#if defined(__TI_COMPILER_VERSION__) || (__IAR_SYSTEMS_ICC__)
#pragma vector=USB_UBM_VECTOR
__interrupt void iUsbInterruptHandler(void)
#elif defined(__GNUC__) && (__MSP430__)
void __attribute__ ((interrupt(USB_UBM_VECTOR))) iUsbInterruptHandler(void)
#endif
{
uint8_t bWakeUp = FALSE;
//Check if the setup interrupt is pending.
//We need to check it before other interrupts,
//to work around that the Setup Int has lower priority then Input Endpoint 0
if (USBIFG & SETUPIFG)
{
bWakeUp = SetupPacketInterruptHandler();
#ifdef USB10_WORKAROUND
tEndPoint0DescriptorBlock.bIEPCNFG &= ~EPCNF_UBME; // Clear ME to gate off SETUPIFG clear event
tEndPoint0DescriptorBlock.bOEPCNFG &= ~EPCNF_UBME; // Clear ME to gate off SETUPIFG clear event
#endif
USBIFG &= ~SETUPIFG; // clear the interrupt bit
#ifdef USB10_WORKAROUND
tEndPoint0DescriptorBlock.bIEPCNFG |= EPCNF_UBME; // Set ME to continue with normal operation
tEndPoint0DescriptorBlock.bOEPCNFG |= EPCNF_UBME; // Set ME to continue with normal operation
#endif
}
switch (__even_in_range(USBVECINT & 0x3f, USBVECINT_OUTPUT_ENDPOINT7))
{
case USBVECINT_NONE:
break;
case USBVECINT_PWR_DROP:
__no_operation();
break;
case USBVECINT_PLL_LOCK:
break;
case USBVECINT_PLL_SIGNAL:
break;
case USBVECINT_PLL_RANGE:
if (wUsbEventMask & USB_CLOCK_FAULT_EVENT)
{
bWakeUp = USB_handleClockEvent();
}
break;
case USBVECINT_PWR_VBUSOn:
PWRVBUSonHandler();
if (wUsbEventMask & USB_VBUS_ON_EVENT)
{
bWakeUp = USB_handleVbusOnEvent();
}
break;
case USBVECINT_PWR_VBUSOff:
PWRVBUSoffHandler();
if (wUsbEventMask & USB_VBUS_OFF_EVENT)
{
bWakeUp = USB_handleVbusOffEvent();
}
break;
case USBVECINT_USB_TIMESTAMP:
break;
case USBVECINT_INPUT_ENDPOINT0:
IEP0InterruptHandler();
break;
case USBVECINT_OUTPUT_ENDPOINT0:
OEP0InterruptHandler();
break;
case USBVECINT_RSTR:
USB_reset();
if (wUsbEventMask & USB_RESET_EVENT)
{
bWakeUp = USB_handleResetEvent();
}
break;
case USBVECINT_SUSR:
USB_suspend();
if (wUsbEventMask & USB_SUSPENDED_EVENT)
{
bWakeUp = USB_handleSuspendEvent();
}
break;
case USBVECINT_RESR:
USB_resume();
if (wUsbEventMask & USB_RESUME_EVENT)
{
bWakeUp = USB_handleResumeEvent();
}
//-- after resume we will wake up! Independ what event handler says.
bWakeUp = TRUE;
break;
case USBVECINT_SETUP_PACKET_RECEIVED:
// NAK both IEP and OEP enpoints
tEndPoint0DescriptorBlock.bIEPBCNT = EPBCNT_NAK;
tEndPoint0DescriptorBlock.bOEPBCNT = EPBCNT_NAK;
SetupPacketInterruptHandler();
break;
case USBVECINT_STPOW_PACKET_RECEIVED:
break;
case USBVECINT_INPUT_ENDPOINT1:
//send saved bytes from buffer...
bWakeUp = HidToHostFromBuffer(HID0_INTFNUM);
break;
case USBVECINT_INPUT_ENDPOINT2:
break;
case USBVECINT_INPUT_ENDPOINT3:
break;
case USBVECINT_INPUT_ENDPOINT4:
break;
case USBVECINT_INPUT_ENDPOINT5:
break;
case USBVECINT_INPUT_ENDPOINT6:
break;
case USBVECINT_INPUT_ENDPOINT7:
break;
case USBVECINT_OUTPUT_ENDPOINT1:
//call callback function if no receive operation is underway
if (!HidIsReceiveInProgress(HID0_INTFNUM))
{
if (wUsbEventMask & USB_DATA_RECEIVED_EVENT)
{
bWakeUp = USBHID_handleDataReceived(HID0_INTFNUM);
}
}
else
{
//complete receive opereation - copy data to user buffer
bWakeUp = HidToBufferFromHost(HID0_INTFNUM);
}
break;
case USBVECINT_OUTPUT_ENDPOINT2:
break;
case USBVECINT_OUTPUT_ENDPOINT3:
break;
case USBVECINT_OUTPUT_ENDPOINT4:
break;
case USBVECINT_OUTPUT_ENDPOINT5:
break;
case USBVECINT_OUTPUT_ENDPOINT6:
break;
case USBVECINT_OUTPUT_ENDPOINT7:
break;
default:
break;
}
if (bWakeUp)
{
__bic_SR_register_on_exit(LPM3_bits); // Exit LPM0-3
__no_operation(); // Required for debugger
}
}
/*----------------------------------------------------------------------------+
| Interrupt Sub-routines |
+----------------------------------------------------------------------------*/
uint8_t SetupPacketInterruptHandler(void)
{
uint8_t bTemp;
uint8_t bWakeUp = FALSE;
USBCTL |= FRSTE; // Function Reset Connection Enable - set enable after first setup packet was received
usbProcessNewSetupPacket:
// copy the MSB of bmRequestType to DIR bit of USBCTL
if((tSetupPacket.bmRequestType & USB_REQ_TYPE_INPUT) == USB_REQ_TYPE_INPUT)
{
USBCTL |= DIR;
}
else
{
USBCTL &= ~DIR;
}
bStatusAction = STATUS_ACTION_NOTHING;
// clear out return data buffer
for(bTemp=0; bTemp<USB_RETURN_DATA_LENGTH; bTemp++)
{
abUsbRequestReturnData[bTemp] = 0x00;
}
// decode and process the request
bWakeUp = usbDecodeAndProcessUsbRequest();
// check if there is another setup packet pending
// if it is, abandon current one by NAKing both data endpoint 0
if((USBIFG & STPOWIFG) != 0x00)
{
USBIFG &= ~(STPOWIFG | SETUPIFG);
goto usbProcessNewSetupPacket;
}
return bWakeUp;
}
//----------------------------------------------------------------------------
void PWRVBUSoffHandler(void)
{
uint16_t MCLKFreq = USB_determineFreq();
uint16_t DelayConstant_250us = ((MCLKFreq >> 6) + (MCLKFreq >> 7) + (MCLKFreq >> 9));
volatile uint16_t i, j;
//wait 1 ms till enable USB
for(j = 0; j < 4; j++)
{
for (i = 0; i < (DelayConstant_250us); i++){
_NOP();
}
}
if (!(USBPWRCTL & USBBGVBV))
{
USBKEYPID = 0x9628; // set KEY and PID to 0x9628 -> access to configuration registers enabled
bEnumerationStatus = 0x00; // device is not enumerated
bFunctionSuspended = FALSE; // device is not suspended
USBCNF = 0; // disable USB module
USBPLLCTL &= ~UPLLEN; // disable PLL
USBPWRCTL &= ~(VBOFFIE + VBOFFIFG + SLDOEN); // disable interrupt VBUSoff
USBKEYPID = 0x9600; // access to configuration registers disabled
}
}
//----------------------------------------------------------------------------
void PWRVBUSonHandler(void)
{
uint16_t MCLKFreq = USB_determineFreq();
uint16_t DelayConstant_250us = ((MCLKFreq >> 6) + (MCLKFreq >> 7) + (MCLKFreq >> 9));
volatile uint16_t i, j;
//wait 1 ms till enable USB
for(j = 0; j < 4; j++)
{
for (i = 0; i < (DelayConstant_250us); i++){
_NOP();
}
}
if (USBPWRCTL & USBBGVBV) //Checking for USB Bandgap and VBUS valid before modifying USBPWRCTL
{
USBKEYPID = 0x9628; // set KEY and PID to 0x9628 -> access to configuration registers enabled
USBPWRCTL |= VBOFFIE; // enable interrupt VBUSoff
USBPWRCTL &= ~ (VBONIFG + VBOFFIFG); // clean int flag (bouncing)
USBKEYPID = 0x9600; // access to configuration registers disabled
}
}
//----------------------------------------------------------------------------
void IEP0InterruptHandler(void)
{
USBCTL |= FRSTE; // Function Reset Connection Enable
tEndPoint0DescriptorBlock.bOEPBCNT = 0x00;
if(bStatusAction == STATUS_ACTION_DATA_IN)
{
usbSendNextPacketOnIEP0();
}
else
{
tEndPoint0DescriptorBlock.bIEPCNFG |= EPCNF_STALL; // no more data
}
}
//----------------------------------------------------------------------------
uint8_t OEP0InterruptHandler(void)
{
uint8_t bWakeUp = FALSE;
USBCTL |= FRSTE; // Function Reset Connection Enable
tEndPoint0DescriptorBlock.bIEPBCNT = 0x00;
if(bStatusAction == STATUS_ACTION_DATA_OUT)
{
usbReceiveNextPacketOnOEP0();
if(bStatusAction == STATUS_ACTION_NOTHING)
{
# ifdef _CDC_
if(tSetupPacket.bRequest == USB_CDC_SET_LINE_CODING)
{
bWakeUp = Handler_SetLineCoding();
}
# endif
#ifdef _HID_
if (tSetupPacket.bRequest == USB_REQ_SET_REPORT) {
bWakeUp = USBHID_handleEP0SetReportDataAvailable(tSetupPacket.wIndex);
}
#endif
}
}
else
{
tEndPoint0DescriptorBlock.bOEPCNFG |= EPCNF_STALL; // no more data
}
return (bWakeUp);
}
/*----------------------------------------------------------------------------+
| End of source file |
+----------------------------------------------------------------------------*/
/*------------------------ Nothing Below This Line --------------------------*/
//Released_Version_5_20_06_02
Best regards,
Sasaki
