STM8S datasheet(286/467 Pages) STMICROELECTRONICS

286 / 467 page

Serial peripheral interface (SPI)

RM0016

286/467

DocID14587 Rev 14

20.4.5

SPI data register (SPI_DR)

Address offset: 0x04

Reset value: 0x00

20.4.6

SPI CRC polynomial register (SPI_CRCPR)

Address offset: 0x05

Reset value: 0x07

20.4.7

SPI Rx CRC register (SPI_RXCRCR)

Address offset: 0x06Reset value: 0x00

654

3210

DR[7:0]

Bits 7:0 DR[7:0]: Data register

Byte received or to be transmitted.

The data register is split into 2 buffers - one for writing (Transmit buffer) and another one for reading

(Receive buffer). A write to the data register will write into the Tx buffer and a read from the data

654

3210

CRCPOLY[7:0]

Bits 7:0 CRCPOLY[7:0]: CRC polynomial register

This register contains the polynomial for the CRC calculation.

The CRC polynomial (0x07) is the reset value of this register. You can configure an other polynomial

as required for your application.

654

3210

RxCRC[7:0]

Bits 7:0 RXCRC[7:0]: Rx CRC Register

When CRC calculation is enabled, the RxCRC[7:0] bits contain the computed CRC value of the

subsequently received bytes. This register is reset when the CRCEN bit in SPI_CR2 register is written

to 1. The CRC is calculated serially using the polynomial programmed in the SPI_CRCPR register.

Note: A read to this register when the BSY Flag is set could return an incorrect value.

STM8S Datasheet(PDF) 286 Page - STMicroelectronics