Message Reception

Versal ACAP Technical Reference Manual (AM011)

Document ID
AM011
Release Date
2022-04-26
Revision
1.4 English

Whenever a new message (that passes the required filtering) is stored into the RX buffer, the controller updates the respective fill level field of the RxBuff_Status register and sets the APB_MISC_ISR [RXOK] bit.

Software Actions

  1. As per the requirement, program the RxBuff_Watermark register (WMR) to set full water marks and the [RXFP] field (the WMR register can be set/changed only when [CEN] = 0).
  2. If required, enable [RXOK] and [RX] Overflow interrupt generation.
  3. The new message availability can be determined by polling the RxBuff_Status register (FSR) or by a watermark full interrupts indication.
  4. Read a new message (from RX Buffer 0 or RX Buffer 1) starting from its respective read index location (given in the FSR register field).
  5. After reading the message, write the FSR register by setting the respective [IRI] bit to 1. This enables the core to increment the respective read index field by +1 and updates the corresponding fill level in the FSR register. If the fill level is 0, setting the [IRI] bit has no effect.
  6. Repeat steps 3 through 5 until all messages are read from both RX Buffer 0 or RX Buffer 1.

Controller Actions

  1. When a message is successfully received, the core writes the timestamp and matched filtered index field of the received message element.
  2. The controller increments the fill level of its respective RX Buffer in the RxBuff_Status register (FSR) by 1 after every successful receive (without error and message passes filtering scheme).
  3. The fill level is also updated by the core after the host writes the [Bx_IRI] bit of the respective RX buffer in the FSR register.