SPI SPI settings The SPI parameters are to be set as follows (see also the following figure): The idle level of the clock signal is low. A bit value (MISO and MOSI) is made available on the rising edge of the clock signal. The sampling instant is the falling edge of the clock signal. The data are sent and received with the Most Significant Bit first. The CS signal is low active. As long as the SPI slave has not synchronized with the millisecond cycle of the SPI master, the SPI master may only transfer a message every two milliseconds. If the SPI is in sync with the millisecond cycle of the SPI master, the SPI master may transfer a message every millisecond. The SPI slave can be controlled with a maximum frequency of 20 MHz. The following figure shows the SPI signal curve: Bus initialization The slaves do not send valid content until a correct message has been received once from the master. Bus initialization is concluded with the first correctly received message.
SPI settings The SPI parameters are to be set as follows (see also the following figure): The idle level of the clock signal is low. A bit value (MISO and MOSI) is made available on the rising edge of the clock signal. The sampling instant is the falling edge of the clock signal. The data are sent and received with the Most Significant Bit first. The CS signal is low active. As long as the SPI slave has not synchronized with the millisecond cycle of the SPI master, the SPI master may only transfer a message every two milliseconds. If the SPI is in sync with the millisecond cycle of the SPI master, the SPI master may transfer a message every millisecond. The SPI slave can be controlled with a maximum frequency of 20 MHz. The following figure shows the SPI signal curve:
Bus initialization The slaves do not send valid content until a correct message has been received once from the master. Bus initialization is concluded with the first correctly received message.
