satcat5::crc16::KermitTx Class Reference

Detailed Description

Append FCS to each outgoing frame ("KERMIT" variant).

Initial value is usually zero, but 0xFFFF is also common.

See also

crc16_checksum.h, crc16::KermitTx.

Definition at line 45 of file crc16_checksum.h.

#include <crc16_checksum.h>

Inheritance diagram for satcat5::crc16::KermitTx:

Collaboration diagram for satcat5::crc16::KermitTx:

Public Member Functions
	KermitTx (satcat5::io::Writeable *dst, u16 init=0, u16 xorout=0)
bool	write_finalize () override
	Mark end of frame and release temporary working data. More...
unsigned	get_write_space () const override
	How many bytes can be written without blocking? More...
void	write_abort () override
	If possible, abort the current partially-written packet. More...
unsigned	byte_count (bool reset=true) override
	Bytes transferred since the last query.
unsigned	frame_count (bool reset=true) override
	Frames transferred since the last query.
unsigned	error_count (bool reset=true) override
	(Optional) Error events since the last query.
void	byte_incr (unsigned incr)
	Increment any of the internal counters.
void	frame_incr (unsigned incr)
void	error_incr (unsigned incr)
void	write_u8 (u8 data)
	One of many functions for writing integer/floating point values, see details. More...
virtual void	write_bytes (unsigned nbytes, const void *src)
	Write 0 or more bytes from a buffer. More...
void	write_str (const char *str)
	Write the contents of a null-terminated string. More...
template<class T >
void	write_obj (const T &obj)
	Templated wrapper for any object with the following method: void write_to(satcat5::io::Writeable* wr) const;

Protected Member Functions
void	chk_reset () override
	Reset checksum calculation to its initial state.
bool	chk_finalize ()
	Reset internal state and return true if the frame is valid. More...
void	write_overflow () override
	Optional error handling for write overflow. More...

Protected Attributes
u16	m_chk
	Checksum state.
const u16	m_init
	State after reset.
satcat5::io::Writeable *const	m_dst
	Output object.
bool	m_ovr
	Overflow flag.
unsigned	m_byte_ct
	Cumulative byte count.
unsigned	m_err_ct
	Cumulative error count.
unsigned	m_frm_ct
	Cumulative frame count.
unsigned	m_frm_len
	Length of current frame.
friend	LimitedWrite
friend	WriteableBroadcast
friend	WriteableRedirect

Private Member Functions
void	write_next (u8 data) override
	Write the next byte to the underlying buffer or device. More...

Private Attributes
const u16	m_xorout

Member Function Documentation

chk_finalize()

bool ChecksumTxCommon::chk_finalize ( )

protectedinherited

Reset internal state and return true if the frame is valid.

i.e., If false, do not forward the write_finalize() event.

Definition at line 24 of file io_checksum.cc.

get_write_space()

unsigned satcat5::io::ChecksumTx< u16 , N >::get_write_space ( ) const

inlineoverridevirtualinherited

How many bytes can be written without blocking?

Child objects of io::Writeable MUST override this method.

Implements satcat5::io::Writeable.

Definition at line 86 of file io_checksum.h.

write_abort()

void ChecksumTxCommon::write_abort ( )

overridevirtualinherited

If possible, abort the current partially-written packet.

Child objects of io::Writeable SHOULD override this method if it is practical to prevent in-progress data from being relayed downstream.

Reimplemented from satcat5::io::Writeable.

Definition at line 16 of file io_checksum.cc.

write_bytes()

void Writeable::write_bytes ( unsigned  nbytes, const void *  src  )

virtualinherited

Write 0 or more bytes from a buffer.

Child objects of io::Writeable MAY override write_bytes as needed for performance.

Reimplemented in satcat5::port::MailmapAligned, satcat5::port::Mailmap, satcat5::io::PacketBuffer, satcat5::io::MultiWriter, satcat5::io::MultiPacket::Overwriter, satcat5::io::NullWrite, satcat5::io::WriteableRedirect, satcat5::io::LimitedWrite, satcat5::io::CounterInline, satcat5::io::WriteableBroadcast, and satcat5::io::FileWriter.

Definition at line 170 of file io_writeable.cc.

write_finalize()

bool KermitTx::write_finalize ( )

overridevirtual

Mark end of frame and release temporary working data.

Child objects of io::Writeable SHOULD override this method to mark frame bounds.

Returns

True if successful, false on error.

Reimplemented from satcat5::io::Writeable.

Definition at line 176 of file crc16_checksum.cc.

write_next()

void KermitTx::write_next ( u8  data )

overrideprivatevirtual

Write the next byte to the underlying buffer or device.

Child objects of io::Writeable MUST override this method.

Implements satcat5::io::Writeable.

Definition at line 182 of file crc16_checksum.cc.

write_overflow()

void ChecksumTxCommon::write_overflow ( )

overrideprotectedvirtualinherited

Optional error handling for write overflow.

Child objects of io::Writeable MAY override this method for error handling.

Reimplemented from satcat5::io::Writeable.

Definition at line 12 of file io_checksum.cc.

write_str()

void Writeable::write_str ( const char *  str )

inherited

Write the contents of a null-terminated string.

Note: Null-termination is not copied to the output.

Definition at line 180 of file io_writeable.cc.

write_u8()

void Writeable::write_u8 ( u8  data )

inherited

One of many functions for writing integer/floating point values, see details.

Several functions are provided for reading and writing scalar types to/from io::Readable and io::Writeable instances. Since there are many of these that are frequently inherited, they are hidden from documentation. These functions follow a shared template:

• read_ or write_ prefix.
• u for unsigned, s for signed, f for floating-point.
• Data-type width in bits.
  • Available widths for ints: 8/16/24/32/48/64.
  • Available widths for floats: 32/64.
• l suffix if little-endian, no suffix if big-endian.

Example: write_s48l is "Write 48 bits (6 bytes) to this io::Writeable as a signed value in little-endian order".

Definition at line 20 of file io_writeable.cc.

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The documentation for this class was generated from the following files:

• crc16_checksum.h
• crc16_checksum.cc