eqmk
/
qmk_firmware
forked from mfulz_github/qmk_firmware
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Add glitch protection to the software UART in the XPLAINBridge project code, so that very short glitches on the RX line don't cause a frame reception to occur.

This commit is contained in:
Dean Camera 2010-07-12 02:23:11 +00:00
parent 229935184b
commit 3fd246041b
2 changed files with 14 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
Projects/XPLAINBridge/Lib/SoftUART.c
View File

@ -76,15 +76,21 @@ void SoftUART_Init(void)
/** ISR to detect the start of a bit being sent to the software UART. */
ISR(INT0_vect, ISR_BLOCK)
{
/* Reset and start the reception timer */
TCNT1 = 0;
TCCR1B = ((1 << CS10) | (1 << WGM12));
/* Reset the number of reception bits remaining counter */
RX_BitsRemaining = 8;
/* Reset the bit reception timer */
TCNT1 = 0;
/* Disable start bit detection ISR while the next byte is received */
EIMSK = 0;
/* Check to see that the pin is still low (prevents glitches from starting a frame reception) */
if (!(SRXPIN & (1 << SRX)))
{
/* Disable start bit detection ISR while the next byte is received */
EIMSK = 0;
/* Start the reception timer */
TCCR1B = ((1 << CS10) | (1 << WGM12));
}
}
/** ISR to manage the reception of bits to the software UART. */
@ -133,7 +139,7 @@ ISR(TIMER3_COMPA_vect, ISR_NOBLOCK)
TX_Data >>= 1;
TX_BitsRemaining--;
}
else if (USBtoUART_Buffer.Count)
else if (USBtoUART_Buffer.Count && !(RX_BitsRemaining))
{
/* Start bit - TX line low */
STXPORT &= ~(1 << STX);

2
Projects/XPLAINBridge/XPLAINBridge.c
View File

@ -180,7 +180,7 @@ void EVENT_USB_Device_ConfigurationChanged(void)
{
EndpointConfigSuccess &= CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface);
/* Configure the UART flush timer */
/* Configure the UART flush timer - run at FCPU/1024 for maximum interval before overflow */
TCCR0B = ((1 << CS02) | (1 << CS00));
}
else