diff options
Diffstat (limited to 'Projects/AVRISP/Lib/PDITarget.c')
| -rw-r--r-- | Projects/AVRISP/Lib/PDITarget.c | 221 |
1 files changed, 161 insertions, 60 deletions
diff --git a/Projects/AVRISP/Lib/PDITarget.c b/Projects/AVRISP/Lib/PDITarget.c index a0bbf7dfa..9a94e9a4e 100644 --- a/Projects/AVRISP/Lib/PDITarget.c +++ b/Projects/AVRISP/Lib/PDITarget.c @@ -38,90 +38,191 @@ #define INCLUDE_FROM_PDITARGET_C
#include "PDITarget.h"
-/** Writes a given byte to the attached XMEGA device, using a RS232 frame via software through the
- * PDI interface.
- *
- * \param[in] Byte Byte to send to the attached device
- */
-void PDITarget_SendByte(uint8_t Byte)
-{
- uint8_t LogicOneBits = 0;
+#if !defined(PDI_VIA_HARDWARE_USART)
+volatile bool IsSending;
+volatile uint16_t DataBits;
+volatile uint8_t BitCount;
- // One Start Bit
- PDIDATA_LINE_PORT &= ~PDIDATA_LINE_MASK;
+ISR(TIMER0_COMPA_vect, ISR_BLOCK)
+{
+ BITBANG_PDICLOCK_PORT ^= BITBANG_PDICLOCK_MASK;
- TOGGLE_PDI_CLOCK;
+ /* If not sending or receiving, just exit */
+ if (!(BitCount))
+ return;
- // Eight Data Bits
- for (uint8_t i = 0; i < 8; i++)
+ /* Check to see if the current clock state is on the rising or falling edge */
+ bool IsRisingEdge = (BITBANG_PDICLOCK_PORT & BITBANG_PDICLOCK_MASK);
+
+ if (IsSending && !IsRisingEdge)
{
- if (Byte & 0x01)
- {
- PDIDATA_LINE_PORT &= ~PDIDATA_LINE_MASK;
- LogicOneBits++;
- }
+ if (DataBits & 0x01)
+ BITBANG_PDIDATA_PORT &= ~BITBANG_PDIDATA_MASK;
else
- {
- PDIDATA_LINE_PORT |= PDIDATA_LINE_MASK;
- }
-
- Byte >>= 1;
+ BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;
- TOGGLE_PDI_CLOCK;
+ DataBits >>= 1;
+ BitCount--;
}
+ else if (!IsSending && IsRisingEdge)
+ {
+ /* Wait for the start bit when receiving */
+ if ((BitCount == BITS_IN_FRAME) && (BITBANG_PDIDATA_PORT & BITBANG_PDIDATA_MASK))
+ return;
+
+ if (BITBANG_PDIDATA_PORT & BITBANG_PDIDATA_MASK)
+ DataBits |= (1 << (BITS_IN_FRAME - 1));
- // Even Parity Bit
- if (LogicOneBits & 0x01)
- PDIDATA_LINE_PORT &= ~PDIDATA_LINE_MASK;
- else
- PDIDATA_LINE_PORT |= PDIDATA_LINE_MASK;
-
- TOGGLE_PDI_CLOCK;
+ DataBits >>= 1;
+ BitCount--;
+ }
+}
- // Two Stop Bits
- PDIDATA_LINE_PORT |= PDIDATA_LINE_MASK;
+void PDITarget_EnableTargetPDI(void)
+{
+ /* Set DATA and CLOCK lines to outputs */
+ BITBANG_PDIDATA_DDR |= BITBANG_PDIDATA_MASK;
+ BITBANG_PDICLOCK_DDR |= BITBANG_PDICLOCK_MASK;
- TOGGLE_PDI_CLOCK;
- TOGGLE_PDI_CLOCK;
+ /* Set DATA line high for 90ns to disable /RESET functionality */
+ BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;
+ asm volatile ("NOP"::);
+ asm volatile ("NOP"::);
+
+ /* Fire timer compare ISR every 160 cycles */
+ OCR0A = 20;
+ TCCR0A = (1 << WGM01);
+ TCCR0B = (1 << CS01);
+ TIMSK0 = (1 << OCIE0A);
}
-/** Reads a given byte from the attached XMEGA device, encoded in a RS232 frame through the PDI interface.
- *
- * \return Received byte from the attached device
- */
-uint8_t PDITarget_ReceiveByte(void)
+void PDITarget_DisableTargetPDI(void)
{
- uint8_t ReceivedByte = 0;
-
- PDIDATA_LINE_DDR &= ~PDIDATA_LINE_MASK;
+ /* Set DATA and CLOCK lines to inputs */
+ BITBANG_PDIDATA_DDR &= ~BITBANG_PDIDATA_MASK;
+ BITBANG_PDICLOCK_DDR &= ~BITBANG_PDICLOCK_MASK;
+
+ /* Tristate DATA and CLOCK lines */
+ BITBANG_PDIDATA_PORT &= ~BITBANG_PDIDATA_MASK;
+ BITBANG_PDICLOCK_PORT &= ~BITBANG_PDICLOCK_MASK;
- // One Start Bit
- while (PDIDATA_LINE_PIN & PDIDATA_LINE_MASK);
- TOGGLE_PDI_CLOCK;
+ TCCR0B = 0;
+}
- TOGGLE_PDI_CLOCK;
+void PDITarget_SendByte(uint8_t Byte)
+{
+ bool IsOddBitsSet = false;
- // Eight Data Bits
+ /* Compute Even parity bit */
for (uint8_t i = 0; i < 8; i++)
{
- if (!(PDIDATA_LINE_PIN & PDIDATA_LINE_MASK))
- ReceivedByte |= 0x80;
+ if (Byte & (1 << i))
+ IsOddBitsSet = !(IsOddBitsSet);
+ }
- ReceivedByte >>= 1;
+ /* Data shifted out LSB first, START DATA PARITY STOP STOP */
+ DataBits = ((uint16_t)IsOddBitsSet << 10) | ((uint16_t)Byte << 1) | (1 << 0);
- TOGGLE_PDI_CLOCK;
- }
+ BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;
+ BITBANG_PDIDATA_DDR |= BITBANG_PDIDATA_MASK;
- // Even Parity Bit (discarded)
- TOGGLE_PDI_CLOCK;
+ IsSending = true;
+ BitCount = BITS_IN_FRAME;
+ while (BitCount);
+
+ BITBANG_PDIDATA_PORT &= ~BITBANG_PDIDATA_MASK;
+ BITBANG_PDIDATA_DDR &= ~BITBANG_PDIDATA_MASK;
+}
+
+uint8_t PDITarget_ReceiveByte(void)
+{
+ IsSending = false;
+ BitCount = BITS_IN_FRAME;
+ while (BitCount);
+
+ return (DataBits >> 1);
+}
- // Two Stop Bits
- TOGGLE_PDI_CLOCK;
- TOGGLE_PDI_CLOCK;
+void PDITarget_SendBreak(void)
+{
+ DataBits = 0;
+
+ BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;
+ BITBANG_PDIDATA_DDR |= BITBANG_PDIDATA_MASK;
+
+ IsSending = true;
+ BitCount = BITS_IN_FRAME;
+ while (BitCount);
+
+ BITBANG_PDIDATA_PORT &= ~BITBANG_PDIDATA_MASK;
+ BITBANG_PDIDATA_DDR &= ~BITBANG_PDIDATA_MASK;
+}
+#else
+void PDITarget_EnableTargetPDI(void)
+{
+ /* Set Tx and XCK as outputs, Rx as input */
+ DDRD |= (1 << 5) | (1 << 3);
+ DDRD &= ~(1 << 2);
- PDIDATA_LINE_DDR |= PDIDATA_LINE_MASK;
+ /* Set DATA line high for 90ns to disable /RESET functionality */
+ PORTD |= (1 << 3);
+ asm volatile ("NOP"::);
+ asm volatile ("NOP"::);
- return ReceivedByte;
+ /* Set up the synchronous USART for XMEGA communications -
+ 8 data bits, even parity, 2 stop bits */
+ UBRR1 = 10;
+ UCSR1B = (1 << TXEN1);
+ UCSR1C = (1 << UMSEL10) | (1 << UPM11) | (1 << USBS1) | (1 << UCSZ11) | (1 << UCSZ10) | (1 << UCPOL1);
+
+ PDITarget_SendBreak();
+ PDITarget_SendBreak();
}
+void PDITarget_DisableTargetPDI(void)
+{
+ /* Turn of receiver and transmitter of the USART, clear settings */
+ UCSR1B = 0;
+ UCSR1C = 0;
+
+ /* Set all USART lines as input, tristate */
+ DDRD &= ~(1 << 5) | (1 << 3);
+ PORTD &= ~((1 << 5) | (1 << 3) | (1 << 2));
+}
+
+void PDITarget_SendByte(uint8_t Byte)
+{
+ UCSR1B &= ~(1 << RXEN1);
+ UCSR1B |= (1 << TXEN1);
+
+ UDR1 = Byte;
+
+ while (!(UCSR1A & (1 << TXC1)));
+ UCSR1A |= (1 << TXC1);
+}
+
+uint8_t PDITarget_ReceiveByte(void)
+{
+ UCSR1B &= ~(1 << TXEN1);
+ UCSR1B |= (1 << RXEN1);
+
+ while (!(UCSR1A & (1 << RXC1)));
+ UCSR1A |= (1 << RXC1);
+
+ return UDR1;
+}
+
+void PDITarget_SendBreak(void)
+{
+ UCSR1B &= ~(1 << RXEN1);
+ UCSR1B |= (1 << TXEN1);
+
+ for (uint8_t i = 0; i < BITS_IN_FRAME; i++)
+ {
+ while (PIND & (1 << 5));
+ while (!(PIND & (1 << 5)));
+ }
+}
+#endif
+
#endif
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