7.6.28 Read RX FIFO Byte Interrupt

Description

The SPI command “Read RX FIFO Byte Interrupt” returns n bytes of the content of the DFIFO in the RX direction. The desired number of data bytes to be returned is given by the step parameter. The access direction switch of the FIFO is set automatically and restored to the origin at the end of the command (direction temporarily stored in the T-bit).

The SPI command “Read RX FIFO Byte Interrupt” can be used instead of the command “Read RX FIFO” to read the DFIFO content without using the SPI FIFO. The data bytes are read directly from the DFIFO. This can be helpful in timing critical situations where every single byte is fetched in a certain time slot. Due to the bypassing mechanism of the SPI FIFOs, this SPI command only works with data rates up to 250 Kbit/s.

Command Frame

Parameters

• 0x1D – Command ID
• 0x01 – Parameter step
  • 0: Stop reading from DFIFO (next byte is the final byte)
  • 1: Continue reading from DFIFO

Return Values

• events.system – Event byte (for details see SPI command “Get Event Bytes”)
• events.events – Event byte (for details see SPI command “Get Event Bytes”)
• data – Data byte 1
• data – Data byte 2
• …
• data – Data byte n