Struct ccsds_tm_rand_t¶

A pseudo-randomiser: a maximal-length generator and its preset. More...

#include <ccsds_tm.h>

Public Attributes¶

Type	Name
size_t	period
uint32_t	seed
unsigned	stages
uint32_t	taps

Detailed Description¶

131.0-B-6 section 10.4 specifies two, and which one a mission uses is a choice rather than a property of the coding — so it is a configuration, exactly as the inner code and the outer code are. One implementation serves both; only the table changes.

taps is a mask over the register: bit i set means stage i feeds back. The mask is DERIVED from the characteristic polynomial rather than transcribed from its exponents, and the difference is not cosmetic — rand.c records that writing the exponents produced a generator which walked to the all-zero fixed point and passed every structural check except the published prefix.

Public Attributes Documentation¶

variable period¶

size_t ccsds_tm_rand_t::period;

2^stages - 1, since both are maximal

variable seed¶

uint32_t ccsds_tm_rand_t::seed;

preset, loaded at the start of every run

variable stages¶

unsigned ccsds_tm_rand_t::stages;

register width

variable taps¶

uint32_t ccsds_tm_rand_t::taps;

feedback mask over stages bits

The documentation for this class was generated from the following file native/inc/ccsds_tm/ccsds_tm.h