Crc::Crc(const Config &config)
: m_seed(config.seed), m_is_init(true)
{
Sim::SetEnableClockGate(Sim::ClockGate::kCrc, true);
NewInstance(config.seed);
CRC0->CTRL = 0 | CRC_CTRL_TCRC_MASK | CRC_CTRL_TOT(1) | CRC_CTRL_TOTR(1)
| CRC_CTRL_FXOR_MASK;
CRC0->GPOLY = config.polynomial;
}
/*!
* @brief Starts checksum computation.
*
* Configures the CRC module for the specified CRC protocol. @n
* Starts the checksum computation by writing the seed value
*
* @param base CRC peripheral address.
* @param config Pointer to protocol configuration structure.
*/
static void crc_ConfigureAndStart(CRC_Type *base, const crc_module_config_t *config)
{
uint32_t crcControl;
/* pre-compute value for CRC control registger based on user configuraton without WAS field */
crcControl = 0 | CRC_CTRL_TOT(config->writeTranspose) | CRC_CTRL_TOTR(config->readTranspose) |
CRC_CTRL_FXOR(config->complementChecksum) | CRC_CTRL_TCRC(config->crcBits);
/* make sure the control register is clear - WAS is deasserted, and protocol is set */
base->CTRL = crcControl;
/* write polynomial register */
base->GPOLY = config->polynomial;
/* write pre-computed control register value along with WAS to start checksum computation */
base->CTRL = crcControl | CRC_CTRL_WAS(true);
/* write seed (initial checksum) */
base->DATA = config->seed;
/* deassert WAS by writing pre-computed CRC control register value */
base->CTRL = crcControl;
}
