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AT32F435/437
Series Reference Manual
2022.11.11
Page 621
Rev 2.03
When this bit is cleared, the address filter will ignore the
address for filtering.
Bit 30
SA
0x0
rw
Source Address
When this bit is set, the MAC address 3 [47: 0] is used for
comparison with the source address field of the received
frame.
When this bit is cleared, the MAC address 3 [47: 0] is used
for comparison with the destination address field of the
received frame.
Bit 29: 24 MBC
0x00
rw
Mask Byte Control
These bits are mask control bits for comparison with each
of the MAC address bytes.
When this bit is set, the MAC does not compare the
corresponding byte of the received DA/SA with the
contents of the MAC address 3 register. Each control bit is
used for controlling the mask of the bytes as follows:
Bit 29: EMAC_MACA3H [15: 8]
Bit 28: EMAC_MACA3H [7: 0]
Bit 27: EMAC_MACA3L[31: 24]
...
Bit 24: EMAC_MACA3L[7: 0]
It is possible to filter group addresses (that is, group
address filtering) by masking one or more bytes of the
address.
Bit 23: 16 Reserved
0x00
resd
Kept at its default value.
Bit 15: 0
MA3H
0xFFFF
rw
MAC Address3 High [47: 32]
These bits contain the lower 16 bits (47: 32) of the 6-byte
second MAC address.
26.3.20 Ethernet MAC address 3 low register (EMAC_MACA3L)
The Ethernet MAC address 3 low register holds the lower 32 bits of the 6-byte second MAC address.
Bit
Register
Reset value
Type
Description
Bit 31: 0
MA3L
0xFFFF FFFF rw
MAC Address3 Low [31: 0]
These bits contain the lower 32 bits of the 6-byte second
MAC address. The contents of this field is undefined until
loaded by the application after the initialization process.
26.3.21 Ethernet DMA bus mode register (EMAC_DMABM)
The Ethernet DMA bus mode register defines the bus operation modes for the DMA.
Bit
Register
Reset value
Type
Description
Bit 31: 26 Reserved
0x00
resd
Kept at its default value.
Bit 25
AAB
0x0
rw
Address-Aligned Beats
When this bit is set and the FB bit equals 1, the AHB
interface generates burst transfers aligned to the start
address LS bits. If the FB bit equals 0, the first burst
transfer (accessing the data buffer’s start address) is not
aligned, but subsequent burst transfers are aligned to the
address.
This bit is applicable to GMAC-AHB and GMAC-AXI
configurations only. It is reserved in other configurations.
Bit 24
PBLx8
0x0
rw
PBLx8 Mode
When this bit is set, this bit multiples the PBL value
programmed (bits [22: 17] and bits [13: 8] ) by 8. Thus the
DMA transfers data at 8, 16, 32, 64, 128 and 256 beats
depending on the PBL value.
Bit 23
USP
0x0
rw
Use separate PBL
When this bit is set, the Rx DMA uses the value
programmed in bit [22: 17] as PBL. The PBL value in bit
[13: 8] is applicable to Tx DMA operations only.
When this bit is cleared, the PBL value in bit [13: 8] is
applicable to both Tx DMA and Rx DMA operations.
Bit 22: 17 RDP
0x01
rw
Rx DMA PBL