@ -41,15 +41,16 @@
volatile bool IsSending ;
# if !defined(PDI_VIA_HARDWARE_USART)
volatile uint16_t DataBits ;
volatile uint8_t BitCount;
volatile uint16_t SoftUSART_ Data;
volatile uint8_t SoftUSART_ BitCount;
ISR ( TIMER0_COMPA_vect , ISR_BLOCK )
{
BITBANG_PDICLOCK_PORT ^ = BITBANG_PDICLOCK_MASK ;
/* Toggle CLOCK pin in a single cycle (see AVR datasheet) */
BITBANG_PDICLOCK_PIN | = BITBANG_PDICLOCK_MASK ;
/* If not sending or receiving, just exit */
if ( ! ( BitCount) )
if ( ! ( SoftUSART_ BitCount) )
return ;
/* Check to see if the current clock state is on the rising or falling edge */
@ -57,115 +58,37 @@ ISR(TIMER0_COMPA_vect, ISR_BLOCK)
if ( IsSending & & ! IsRisingEdge )
{
if ( DataBits & 0x01 )
BITBANG_PDIDATA_PORT & = ~ BITBANG_PDIDATA_MASK ;
else
if ( SoftUSART_Data & 0x01 )
BITBANG_PDIDATA_PORT | = BITBANG_PDIDATA_MASK ;
else
BITBANG_PDIDATA_PORT & = ~ BITBANG_PDIDATA_MASK ;
DataBits > > = 1 ;
BitCount- - ;
SoftUSART_ Data > > = 1 ;
SoftUSART_ BitCount- - ;
}
else if ( ! IsSending & & IsRisingEdge )
{
/* Wait for the start bit when receiving */
if ( ( BitCount = = BITS_IN_FRAME ) & & ( BITBANG_PDIDATA_P ORT & BITBANG_PDIDATA_MASK ) )
if ( ( SoftUSART_ BitCount = = BITS_IN_FRAME ) & & ( BITBANG_PDIDATA_P IN & BITBANG_PDIDATA_MASK ) )
return ;
if ( BITBANG_PDIDATA_PORT & BITBANG_PDIDATA_MASK )
DataBits | = ( 1 < < ( BITS_IN_FRAME - 1 ) ) ;
DataBits > > = 1 ;
BitCount - - ;
}
}
void PDITarget_EnableTargetPDI ( void )
{
/* Set DATA and CLOCK lines to outputs */
BITBANG_PDIDATA_DDR | = BITBANG_PDIDATA_MASK ;
BITBANG_PDICLOCK_DDR | = BITBANG_PDICLOCK_MASK ;
/* 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 ) ;
}
void PDITarget_DisableTargetPDI ( void )
{
/* 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 ;
if ( BITBANG_PDIDATA_PIN & BITBANG_PDIDATA_MASK )
SoftUSART_Data | = ( 1 < < BITS_IN_FRAME ) ;
TCCR0B = 0 ;
SoftUSART_Data > > = 1 ;
SoftUSART_BitCount - - ;
}
void PDITarget_SendByte ( uint8_t Byte )
{
bool IsOddBitsSet = false ;
/* Compute Even parity bit */
for ( uint8_t i = 0 ; i < 8 ; i + + )
{
if ( Byte & ( 1 < < i ) )
IsOddBitsSet = ! ( IsOddBitsSet ) ;
}
# endif
/* Data shifted out LSB first, START DATA PARITY STOP STOP */
DataBits = ( ( uint16_t ) IsOddBitsSet < < 10 ) | ( ( uint16_t ) Byte < < 1 ) | ( 1 < < 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 ;
}
uint8_t PDITarget_ReceiveByte ( void )
{
IsSending = false ;
BitCount = BITS_IN_FRAME ;
while ( BitCount ) ;
return ( DataBits > > 1 ) ;
}
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 )
{
# if defined(PDI_VIA_HARDWARE_USART)
/* Set Tx and XCK as outputs, Rx as input */
DDRD | = ( 1 < < 5 ) | ( 1 < < 3 ) ;
DDRD & = ~ ( 1 < < 2 ) ;
/* Set DATA line high for 90ns to disable /RESET functionality */
/* Set DATA line high for at least 90ns to disable /RESET functionality */
PORTD | = ( 1 < < 3 ) ;
asm volatile ( " NOP " : : ) ;
asm volatile ( " NOP " : : ) ;
@ -179,10 +102,30 @@ void PDITarget_EnableTargetPDI(void)
/* Send two BREAKs of 12 bits each to enable PDI interface (need at least 16 idle bits) */
PDITarget_SendBreak ( ) ;
PDITarget_SendBreak ( ) ;
# else
/* Set DATA and CLOCK lines to outputs */
BITBANG_PDIDATA_DDR | = BITBANG_PDIDATA_MASK ;
BITBANG_PDICLOCK_DDR | = BITBANG_PDICLOCK_MASK ;
/* Set DATA line high for at least 90ns to disable /RESET functionality */
BITBANG_PDIDATA_PORT | = BITBANG_PDIDATA_MASK ;
asm volatile ( " NOP " : : ) ;
asm volatile ( " NOP " : : ) ;
/* Fire timer compare ISR every 50 cycles to manage the software USART */
OCR0A = 50 ;
TCCR0A = ( 1 < < WGM01 ) ;
TCCR0B = ( 1 < < CS00 ) ;
TIMSK0 = ( 1 < < OCIE0A ) ;
PDITarget_SendBreak ( ) ;
PDITarget_SendBreak ( ) ;
# endif
}
void PDITarget_DisableTargetPDI ( void )
{
# if defined(PDI_VIA_HARDWARE_USART)
/* Turn off receiver and transmitter of the USART, clear settings */
UCSR1A | = ( 1 < < TXC1 ) | ( 1 < < RXC1 ) ;
UCSR1B = 0 ;
@ -191,10 +134,22 @@ void PDITarget_DisableTargetPDI(void)
/* Set all USART lines as input, tristate */
DDRD & = ~ ( ( 1 < < 5 ) | ( 1 < < 3 ) ) ;
PORTD & = ~ ( ( 1 < < 5 ) | ( 1 < < 3 ) | ( 1 < < 2 ) ) ;
# else
/* 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 ;
TCCR0B = 0 ;
# endif
}
void PDITarget_SendByte ( uint8_t Byte )
{
# if defined(PDI_VIA_HARDWARE_USART)
/* Switch to Tx mode if currently in Rx mode */
if ( ! ( IsSending ) )
{
@ -210,10 +165,37 @@ void PDITarget_SendByte(uint8_t Byte)
/* Wait until there is space in the hardware Tx buffer before writing */
while ( ! ( UCSR1A & ( 1 < < UDRE1 ) ) ) ;
UDR1 = Byte ;
# else
/* Switch to Tx mode if currently in Rx mode */
if ( ! ( IsSending ) )
{
BITBANG_PDIDATA_PORT | = BITBANG_PDIDATA_MASK ;
BITBANG_PDIDATA_DDR | = BITBANG_PDIDATA_MASK ;
IsSending = true ;
}
bool EvenParityBit = false ;
uint8_t ParityData = Byte ;
/* Compute Even parity bit */
for ( uint8_t i = 0 ; i < 8 ; i + + )
{
EvenParityBit ^ = ParityData & 0x01 ;
ParityData > > = 1 ;
}
while ( SoftUSART_BitCount ) ;
/* Data shifted out LSB first, START DATA PARITY STOP STOP */
SoftUSART_Data = ( ( uint16_t ) EvenParityBit < < 9 ) | ( ( uint16_t ) Byte < < 1 ) | ( 1 < < 10 ) | ( 1 < < 11 ) ;
SoftUSART_BitCount = BITS_IN_FRAME ;
# endif
}
uint8_t PDITarget_ReceiveByte ( void )
{
# if defined(PDI_VIA_HARDWARE_USART)
/* Switch to Rx mode if currently in Tx mode */
if ( IsSending )
{
@ -232,10 +214,30 @@ uint8_t PDITarget_ReceiveByte(void)
/* Wait until a byte has been received before reading */
while ( ! ( UCSR1A & ( 1 < < RXC1 ) ) ) ;
return UDR1 ;
# else
/* Switch to Rx mode if currently in Tx mode */
if ( IsSending )
{
while ( SoftUSART_BitCount ) ;
BITBANG_PDIDATA_DDR & = ~ BITBANG_PDIDATA_MASK ;
BITBANG_PDIDATA_PORT & = ~ BITBANG_PDIDATA_MASK ;
IsSending = false ;
}
/* Wait until a byte has been received before reading */
SoftUSART_BitCount = BITS_IN_FRAME ;
while ( SoftUSART_BitCount ) ;
/* Throw away the start, parity and stop bits to leave only the data */
return ( uint8_t ) ( SoftUSART_Data > > 1 ) ;
# endif
}
void PDITarget_SendBreak ( void )
{
# if defined(PDI_VIA_HARDWARE_USART)
/* Switch to Tx mode if currently in Rx mode */
if ( ! ( IsSending ) )
{
@ -251,13 +253,62 @@ void PDITarget_SendBreak(void)
/* Need to do nothing for a full frame to send a BREAK */
for ( uint8_t i = 0 ; i < = BITS_IN_FRAME ; i + + )
{
/* Wait for rising edge of clock */
/* Wait for a full cycle of the clock */
while ( PIND & ( 1 < < 5 ) ) ;
/* Wait for falling edge of clock */
while ( ! ( PIND & ( 1 < < 5 ) ) ) ;
}
# else
/* Switch to Tx mode if currently in Rx mode */
if ( ! ( IsSending ) )
{
BITBANG_PDIDATA_PORT | = BITBANG_PDIDATA_MASK ;
BITBANG_PDIDATA_DDR | = BITBANG_PDIDATA_MASK ;
IsSending = true ;
}
while ( SoftUSART_BitCount ) ;
/* Need to do nothing for a full frame to send a BREAK */
SoftUSART_Data = 0x0FFF ;
SoftUSART_BitCount = BITS_IN_FRAME ;
# endif
}
void PDITarget_SendAddress ( uint32_t Address )
{
PDITarget_SendByte ( Address > > 24 ) ;
PDITarget_SendByte ( Address > > 26 ) ;
PDITarget_SendByte ( Address > > 8 ) ;
PDITarget_SendByte ( Address & 0xFF ) ;
}
bool PDITarget_WaitWhileNVMBusBusy ( void )
{
uint8_t AttemptsRemaining = 255 ;
/* Poll the STATUS register to check to see if NVM access has been enabled */
while ( AttemptsRemaining - - )
{
PDITarget_SendByte ( PDI_CMD_LDCS | PDI_STATUS_REG ) ;
if ( PDITarget_ReceiveByte ( ) & PDI_STATUS_NVM )
return true ;
}
return false ;
}
void PDITarget_WaitWhileNVMControllerBusy ( void )
{
/* Poll the NVM STATUS register to check to see if NVM controller is busy */
for ( ; ; )
{
PDITarget_SendByte ( PDI_CMD_LDS | ( PDI_DATSIZE_1BYTE < < 2 ) ) ;
PDITarget_SendAddress ( DATAMEM_BASE | DATAMEM_NVM_BASE | 0x0F ) ;
if ( ! ( PDITarget_ReceiveByte ( ) & ( 1 < < 7 ) ) )
return ;
}
}
# endif