MEDIATEK Ralink MT7620 - Page 204

PGMT7620_V.1.0_040503
Page 204 of 523
MT7620 PROGRAMMING GUIDE
Integrated 802.11n MAC/BBP and 2.4 GHz RF/FEM Router-on-a-Chip
2.19.5 PDMA FIFO-like Ring Concept
TX_PKT #l
TX_PKT #k
TX_PKT #j
TX_PKT #i
TX_CTX_IDX (i)
points to non-
transmitted CPU TSD
TX_DTX_IDX (i)
points to non-
transmitted DMA TSD
TX_CRLS_IDX(i)*
points to non-
released TSD
TX_DMA
TX_DMA_EN
TX_DMA_BUSY
RX_PKT #a
RX_PKT #b
RX_PKT #c
RX_DMA
RX_CRX_IDX(j)
points to non-
received CPU FSD
RX_PKT #d
RX_DRX_IDX (j)
points to non-
received DMA FSD
RX_CALC_IDX(j)
points to non-
allocated FSD
TX_Driver RX_Driver
RX_DMA_EN
RX_DMA_BUSY
TX_DONE_INT(i)
RX_DONE_INT(j)
(i=0-1)
(j=0)
PDMA_DLY_INT
NOTE:
1. TX_CRLS_IDX(i) and RX_CRX_IDX (j) are not Located in PDMA hardware,
they are resident in CPU local memory.
2.
RXQ0: For GE MAC receive
TXQ0: GE MAC low priority queue
TXQ1: GE MAC high priority queue
PDMA/Frame Engine
Software Driver
TX_MAX_CNT(i)
RX_MAX_CNT
Figure 2-26 PDMA FIFO-like Ring Concept