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Field
Name
R/W
Description
When reset to low level, the PBL value in bit [13:8] is applicable to two
kinds of DMA engines.
24
PBLx4
R/W
PBLx4 Mode
When set to high level, this bit will multiply the programmed PBL value
by four times. Therefore, the DMA will transmit data at a maximum
beam number of 4, 8, 16, 32, 64 and 128 according to the PBL value.
25
AAL
R/W
Address-Aligned Beats
When this bit is set to high level and the FB bit is equal to 1, the AHB
interface will generate all bursts aligned with the LS bit of the start
address. If the FB bit is equal to 0, the first burst (the start address of
the access data buffer) is misaligned, but the subsequent bursts are
aligned to this address.
26
MB
R/W
Mixed Burst
When this bit is set to high level and the FB bit is set to low level, the
AHB main interface will start all burst INCR with a length of more than
16, and it will recover to a fixed burst with a burst length of 16 or less.
31:27
Reserved
Transmit poll demand register (ETH_DMATXPD)
Offset address: 0x1004
Reset value: 0x0000 0000
Field
Name
R/W
Description
31:0
TXPD
R/W
Transmit Poll Demand
When these bits are written with any value, DMA will read the
current descriptor pointed to by the ETH_DMAHTXD register. If the
descriptor is not available, the pending state will be transmitted and
returned and the bit [2] of the ETH_DMASTS register will be set. If
the descriptor is available, continue to transmit.
Receive poll demand register (ETH_DMARXPD)
Offset address: 0x1008
Reset value: 0x0000 0000
Field
Name
R/W
Description
31:0
RXPD
R/W
Receive Poll Demand
When these bits are written with any value, DMA will read the current
descriptor pointed to by the ETH_DMAHRXD register. If the descriptor
is not available (owned by the host), the pending state will be
transmitted and returned and the bit [7] of the ETH_DMASTS register
will be set. If the descriptor is available, Rx DMA will return to active
state.
Receive descriptor list address register (ETH_DMARXDLADDR)
Offset address: 0x100C
Reset value: 0x0000 0000