// sends all accumulated events. if a xmit fifo is empty then this call returns in about 14us.
// it takes about 860us if we send 225 events.
void sendEvents(){
// EA=0; //USB_Int_Disable(); // disable USB interrupt while writing buffer to FIFO
LedBlueOn(); // toggle LED on each packet
EIE1 &= ~0x02;
Block_Write((BYTE*)AEBuffer, AECounter*4);
EIE1 |= 0x02;
AECounter=0; // reset counter and pointer for event buffering
AEPtr=AEBuffer;
LedBlueOff(); // toggle LED on each packet
// EA=1; //USB_Int_Enable();
}
void LedTest(void)
{
while(1)
{
LedRedOn();
DelayNmS(200);
LedRedOff();
DelayNmS(200);
LedBlueOn();
DelayNmS(200);
LedBlueOff();
DelayNmS(200);
}
}
void DisplayOK(void)
{
unsigned char i = 0;
for(i=0;i<3;i++)
{
BellOn();
LedBlueOn();
DelayNmS(50);
BellOff();
LedBlueOff();
DelayNmS(50);
}
}
void DisplayErr(void)
{
unsigned char i = 0;
for(i=0;i<2;i++)
{
BellOn();
LedRedOn();
LedBlueOn();
DelayNmS(200);
BellOff();
LedRedOff();
LedBlueOff();
DelayNmS(200);
}
}
void LedInit(void)
{
LedRedOff();
LedBlueOff();
}
//-----------------------------------------------------------------------------
// Main Routine
// after initialization, the program simply polls the !req input and when
// !req goes low, !ack on P0.1 is lowered to acknowledge,
// the address is captured in P1 (AE0-7) and P2 (AE8-15) and is copied to XRAM.
// Then !ack is raised, we wait for !req to go high and start over.
// When we get an interrupt from USB, we transmit the existing buffer of data.
//-----------------------------------------------------------------------------
void main(void)
{
PCA0MD &= ~0x40; // Disable Watchdog timer
//void USB_Init (int VendorID, int ProductID, uchar *ManufacturerStr,uchar *ProductStr, uchar *SerialNumberStr, byte MaxPower, byte PwAttributes, uint bcdDevice)
// note that ProductID is important that windows hardware installation wizard can find the USBXPress driver
// this driver must be preinstalled before plugging in device
// see the Preinstaller but note that path in .ini file may need to be changed for preinstaller to locate driver files
// so that they can be copied to standard windows driver search folder for drivers.
// this initVariables is for 60mA device, bus powered, serial number 1.00
USB_Init (0, 0xEA61, ManufacturerStr, ProductStr, SerialNumberStr,250,0x80,0x0100);
CLKSEL |= 0x02; // system clock 24MHz (48MHz USB/2)
RSTSRC |= 0x02; // power on reset
Timer_Init(); // Init Timer and Capture for event timing. Init PCA peripheral before port init.
Port_Init(); // Initialize crossbar and GPIO
initVariables();
LedGreenOff();
LedBlueOff();
/*
LedRedOn();
delay();
LedRedOff();
LedGreenOn();
delay();
LedGreenOff();
LedBlueOn();
delay();
LedBlueOff();
*/
//flushEvents(); // flush some events in case the sender has been powered up
//state=ST_WAITING;
isActive=0;
USB_Int_Enable(); // Enable USB_API Interrupts
while (1){
// if(state==ST_ACTIVE){
if(isActive){
while(NOTREQ==1) { // wait for !req low
if( TH1==0xFF){ // while polling req, check if we have wrapped timer1 since last transfer
if(AECounter>0){
sendEvents(); // if so just send available events
}
}
}
LedGreenOn(); // got req
NOTACK=0; // lower acknowledge
//USB_Int_Disable(); // using these functions increases cycle time to >8us
EA=0; // disable interrupts during snapshot of AE to avoid USB interrupt during snapshot
//note according to C51 compiler specs, shorts are stored big-endian, MSB comes first
*AEPtr++=P2; // AE8-15
*AEPtr++=P1; // AE07
*AEPtr++=PCA0CPH0; // captured PCA counter/timer MSB. This was captured by req low.
*AEPtr++=PCA0CPL0; // timer LSB.
AECounter++; // increment counter for events
EA=1; // reenable interrupts
// USB_Int_Enable(); // using these functions increases cycle time to >8us
// if the retina is powered off, then its req will be low (no power). so this code will come here and
// will have lowered ack and stored a bogus address. now it will wait for req to go high.
// but req will be low from the retina and won't go high
// because ack is low. therefore we can get stuck here if the retina is powered on after reset.
while(NOTREQ==0){ // wait for req to go high
if( TH1==0xFF) { // while polling req, check if we have wrapped timer1 since last transfer
TH1=0;
AECounter--; // throw away that event
break; // break from possibly infinite loop. this will raise ack
}
}
NOTACK=1; // raise acknowledge, completing handshake
LedGreenOff(); // got req
if(AECounter==AE_BUFFER_SIZE){
// when we have collected buffer, initiate transfer
// during this 860us no handshaking is occurring
sendEvents();
}
// }else if(state==ST_WAITING){
}else{ // isActive is false, USB not open, just handshake
// plain handshake cycle is about 1+/-0.2us
while(NOTREQ==1) { // wait for !req low
if( TH1==0xFF) { // while polling req, check if we have wrapped timer1 since last transfer
TH1=0;
NOTACK=0;
NOTACK=1; // toggle ack an extra time in case we are stuck
}
}
LedGreenOn(); // !req received
NOTACK=0; // lower acknowledge
while(NOTREQ==0){ // wait for req to go high
if( TH1==0xFF) { // while polling req, check if we have wrapped timer1 since last transfer
TH1=0;
break; // break from possibly infinite loop
}
}
NOTACK=1; // raise acknowledge, completing handshake
LedGreenOff();
}
}
}
