/*********************************************************************************
Function:
BYTE MSDTasks(void)
Summary:
This function runs the MSD class state machines and all of its
sub-systems. This function should be called periodically once the
device is in the configured state in order to keep the MSD state
machine going.
Description:
This function runs the MSD class state machines and all of its
sub-systems. This function should be called periodically once the
device is in the configured state in order to keep the MSD state
machine going.
Typical Usage:
<code>
void main(void)
{
USBDeviceInit();
while(1)
{
USBDeviceTasks();
if((USBGetDeviceState() \< CONFIGURED_STATE) ||
(USBIsDeviceSuspended() == TRUE))
{
//Either the device is not configured or we are suspended
// so we don't want to do execute any application code
continue; //go back to the top of the while loop
}
else
{
//Keep the MSD state machine going
MSDTasks();
//Run application code.
UserApplication();
}
}
}
</code>
Conditions:
None
Return Values:
BYTE - the current state of the MSD state machine the valid values are
defined in MSD.h under the MSDTasks state machine declaration section.
The possible values are the following\:
* MSD_WAIT
* MSD_DATA_IN
* MSD_DATA_OUT
* MSD_SEND_CSW
Remarks:
None
*********************************************************************************/
BYTE MSDTasks(void)
{
BYTE i;
switch(MSD_State)
{
case MSD_WAIT:
{
//If the MSD state machine is waiting for something to happen
if(!USBHandleBusy(USBMSDOutHandle))
{
//If we received an OUT packet from the host
// then copy the data from the buffer to a global
// buffer so that we can keep the information but
// reuse the buffer
gblCBW.dCBWSignature=msd_cbw.dCBWSignature;
gblCBW.dCBWTag=msd_cbw.dCBWTag;
gblCBW.dCBWDataTransferLength=msd_cbw.dCBWDataTransferLength;
gblCBW.bCBWFlags=msd_cbw.bCBWFlags;
gblCBW.bCBWLUN=msd_cbw.bCBWLUN;
gblCBW.bCBWCBLength=msd_cbw.bCBWCBLength; // 3 MSB are zero
for (i=0;i<msd_cbw.bCBWCBLength;i++)
{
gblCBW.CBWCB[i]=msd_cbw.CBWCB[i];
}
gblCBWLength=USBHandleGetLength(USBMSDOutHandle);
//If this CBW is valid?
if ((gblCBWLength==MSD_CBW_SIZE)&&(gblCBW.dCBWSignature==0x43425355))
{
//Is this CBW meaningful?
if((gblCBW.bCBWLUN<=0x0f)
&&(gblCBW.bCBWCBLength<=0x10)
&&(gblCBW.bCBWCBLength>=0x01)
&&(gblCBW.bCBWFlags==0x00||gblCBW.bCBWFlags==0x80))
{
//Prepare the CSW to be sent
msd_csw.dCSWTag=gblCBW.dCBWTag;
msd_csw.dCSWSignature=0x53425355;
/* If direction is device to host*/
if (gblCBW.bCBWFlags==0x80)
{
MSD_State=MSD_DATA_IN;
}
else if (gblCBW.bCBWFlags==0x00)
{
/* If direction is host to device*/
/* prepare to read data in msd_buffer */
MSD_State=MSD_DATA_OUT;
}
}
}
}
break;
}
case MSD_DATA_IN:
if(MSDProcessCommand() == MSD_COMMAND_WAIT)
{
// Done processing the command, send the status
MSD_State = MSD_SEND_CSW;
}
break;
case MSD_DATA_OUT:
if(MSDProcessCommand() == MSD_COMMAND_WAIT)
{
/* Finished receiving the data prepare and send the status */
if ((msd_csw.bCSWStatus==0x00)&&(msd_csw.dCSWDataResidue!=0))
{
msd_csw.bCSWStatus=0x02;
}
MSD_State = MSD_SEND_CSW;
}
break;
case MSD_SEND_CSW:
if(USBHandleBusy(USBMSDInHandle))
{
//The TX buffer is not ready to send the status yet.
break;
}
USBMSDInHandle = USBTxOnePacket(MSD_DATA_IN_EP,(BYTE*)&msd_csw,MSD_CSW_SIZE);
//Get ready for next command to come in
if(!USBHandleBusy(USBMSDOutHandle))
{
USBMSDOutHandle = USBRxOnePacket(MSD_DATA_OUT_EP,(BYTE*)&msd_cbw,sizeof(msd_cbw));
}
MSD_State=MSD_WAIT;
break;
}
return MSD_State;
}
/*********************************************************************************
Function:
BYTE MSDTasks(void)
Summary:
This function runs the MSD class state machines and all of its
sub-systems. This function should be called periodically once the
device is in the configured state in order to keep the MSD state
machine going.
Description:
This function runs the MSD class state machines and all of its
sub-systems. This function should be called periodically once the
device is in the configured state in order to keep the MSD state
machine going.
Typical Usage:
<code>
void main(void)
{
USBDeviceInit();
while(1)
{
USBDeviceTasks();
if((USBGetDeviceState() \< CONFIGURED_STATE) ||
(USBIsDeviceSuspended() == TRUE))
{
//Either the device is not configured or we are suspended
// so we don't want to do execute any application code
continue; //go back to the top of the while loop
}
else
{
//Keep the MSD state machine going
MSDTasks();
//Run application code.
UserApplication();
}
}
}
</code>
Conditions:
None
Return Values:
BYTE - the current state of the MSD state machine the valid values are
defined in MSD.h under the MSDTasks state machine declaration section.
The possible values are the following\:
* MSD_WAIT
* MSD_DATA_IN
* MSD_DATA_OUT
* MSD_SEND_CSW
Remarks:
None
*********************************************************************************/
BYTE MSDTasks(void)
{
BYTE i;
switch(MSD_State)
{
case MSD_WAIT:
{
//If the MSD state machine is waiting for something to happen
if(!USBHandleBusy(USBMSDOutHandle))
{
//If we received an OUT packet from the host
// then copy the data from the buffer to a global
// buffer so that we can keep the information but
// reuse the buffer
gblCBW.dCBWSignature=msd_cbw.dCBWSignature;
gblCBW.dCBWTag=msd_cbw.dCBWTag;
gblCBW.dCBWDataTransferLength=msd_cbw.dCBWDataTransferLength;
gblCBW.bCBWFlags=msd_cbw.bCBWFlags;
gblCBW.bCBWLUN=msd_cbw.bCBWLUN;
gblCBW.bCBWCBLength=msd_cbw.bCBWCBLength; // 3 MSB are zero
for (i=0;i<msd_cbw.bCBWCBLength;i++)
{
gblCBW.CBWCB[i]=msd_cbw.CBWCB[i];
}
gblCBWLength=USBHandleGetLength(USBMSDOutHandle);
//If this CBW is valid?
if ((gblCBWLength==MSD_CBW_SIZE)&&(gblCBW.dCBWSignature==0x43425355))
{
//Is this CBW meaningful?
if((gblCBW.bCBWLUN<=0x0f)
&&(gblCBW.bCBWCBLength<=0x10)
&&(gblCBW.bCBWCBLength>=0x01)
&&(gblCBW.bCBWFlags==0x00||gblCBW.bCBWFlags==0x80))
{
//Prepare the CSW to be sent
msd_csw.dCSWTag=gblCBW.dCBWTag;
msd_csw.dCSWSignature=0x53425355;
//Keep track of retry attempts, in case of temporary failures
//during processing of a command.
MSDRetryAttempt = 0;
//Check the command. With the exception of the REQUEST_SENSE
//command, we should reset the sense key info for each new command block.
//Assume the command will get processed successfully (and hence "NO SENSE"
//response, which is used for success cases), unless handler code
//later on detects some kind of error. If it does, it should
//update the sense keys to reflect the type of error detected,
//prior to sending the CSW.
if(gblCBW.CBWCB[0] != MSD_REQUEST_SENSE)
{
gblSenseData[LUN_INDEX].SenseKey=S_NO_SENSE;
gblSenseData[LUN_INDEX].ASC=ASC_NO_ADDITIONAL_SENSE_INFORMATION;
gblSenseData[LUN_INDEX].ASCQ=ASCQ_NO_ADDITIONAL_SENSE_INFORMATION;
}
/* If direction is device to host*/
if (gblCBW.bCBWFlags==0x80)
{
MSD_State=MSD_DATA_IN;
}
else if (gblCBW.bCBWFlags==0x00)
{
/* If direction is host to device*/
/* prepare to read data in msd_buffer */
MSD_State=MSD_DATA_OUT;
}
}
}
}
break;
}
case MSD_DATA_IN:
if(MSDProcessCommand() == MSD_COMMAND_WAIT)
{
// Done processing the command, send the status
MSD_State = MSD_SEND_CSW;
}
break;
case MSD_DATA_OUT:
if(MSDProcessCommand() == MSD_COMMAND_WAIT)
{
/* Finished receiving the data prepare and send the status */
if ((msd_csw.bCSWStatus==0x00)&&(msd_csw.dCSWDataResidue!=0))
{
msd_csw.bCSWStatus=0x02;
}
MSD_State = MSD_SEND_CSW;
}
break;
case MSD_SEND_CSW:
if(USBHandleBusy(USBMSDInHandle))
{
//The TX buffer is not ready to send the status yet.
break;
}
USBMSDInHandle = USBTxOnePacket(MSD_DATA_IN_EP,(BYTE*)&msd_csw,MSD_CSW_SIZE);
//Get ready for next command to come in
if(!USBHandleBusy(USBMSDOutHandle))
{
USBMSDOutHandle = USBRxOnePacket(MSD_DATA_OUT_EP,(BYTE*)&msd_cbw,sizeof(msd_cbw));
}
MSD_State=MSD_WAIT;
break;
default:
//Illegal condition that should not happen, but might occur if the
//device firmware incorrectly calls MSDTasks() prior to calling
//USBMSDInit() during the set-configuration portion of enumeration.
MSD_State=MSD_WAIT;
}
return MSD_State;
}
