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AT32F435/437
Series Reference Manual
2022.11.11
Page 631
Rev 2.03
In this case, the missed frame counter is reset to all zero,
and this bit indicates that a toggle has occurred.
Bit 15: 0
MFC
0x0000
rrc
Missed Frame Counter
This field indicates the number of frames missed by the
controller due to the host receive buffer being unavailable.
This counter is incremented each time the DMA discards
an incoming frame. This bit is cleared when the
mci_be_i[0] bit is set to 1’b1.
26.3.30 Ethernet DMA current transmit descriptor register
(EMAC_DMACTD)
The EMAC_DMACTD register points to the start address of the transmit descriptor being read by the
DMA.
Bit
Register
Reset value
Type
Description
Bit 31: 0
HTDAP
0x0000 0000 ro
Host Transmit Descriptor Address Pointer
These bits are cleared when reset. The DMA updates the
pointer during operation.
26.3.31 Ethernet DMA current receive descriptor register
(EMAC_DMACRD)
The EMAC_DMACRD register points to the start address of the receive descriptor being read by the
DMA.
Bit
Register
Reset value
Type
Description
Bit 31: 0
HRDAP
0x0000 0000 ro
Host Receive Descriptor Address Pointer
These bits are cleared when reset. The DMA updates the
pointer during operation.
26.3.32 Ethernet DMA current transmit buffer address register
(EMAC_DMACTBADDR)
The EMAC_DMACTBADDR register points to the transmit buffer address being read by the DMA.
Bit
Register
Reset value
Type
Description
Bit 31: 0
HTBAP
0x0000 0000 ro
Host Transmit Buffer Address Pointer
These bits are cleared when reset. The DMA updates the
pointer during operation.
26.3.33 Ethernet DMA current receive buffer address register
(EMAC_DMACRBADDR)
The EMAC_DMACRBADDR register points to the receive buffer address being read by the DMA.
Bit
Register
Reset value
Type
Description
Bit 31: 0
HRBAP
0x0000 0000 ro
Host Receive Buffer Address Pointer
These bits are cleared when reset. The DMA updates the
pointer during operation.
26.3.34 Ethernet MMC control register (EMAC_MMCCTRL)
The EMAC_MMCCTRL register defines the operating mode of the management counters.
Bit
Register
Reset value
Type
Description
Bit 31: 4
Reserved
0x0000000
resd
Kept at its default value.
Bit 3
FMC
0x0
rw
Freeze MMC Counter
When this bit is set, it freezes all the MMC counters to their
current value. None of the MMC counters are updated due
to any transmitted or received frame until this bit is set to
0. If the Reset on Read bit is set while the MMC counter is
being read, the counter is also cleared.
Bit 2
RR
0x0
rw
Reset on Read
When this bit is set, the MMC counter is reset to 0 after
being read. The counter is cleared when the least