MIMO OFDM | Documentation? | Packet Buffer

The OFDM core does not contain a packet buffer. Instead, it requires an external 64KB dual-port BRAM be instantiated alongside the core in the overall FPGA hardware design. The OFDM core includes top-level ports which must be tied directly to one port of this BRAM.

Sub-Buffers

The OFDM core divides the 64KB RAM into 32 2KB buffers. User code must specify which of these "sub-buffers" is used for transmitting and receiving packets. The Tx and Rx buffer indicies can be updated at anytime. This approach enables applications like queuing, back-to-back transmissions/receptions and dedicating buffers to particular packets which will be utilized many times. For example, an ACK packet can be generated at boot and loaded into one of the sub-buffers. Data packets would be loaded into a different buffer. Then, whenever the MAC protocol needs to send an ACK, it need only update the addresses of the prepared ACK, then trigger transmission from the dedicated ACK buffer.

User code must avoid changing the selected Tx/Rx buffers during a packet transmission or reception.