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UM10503
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© NXP B.V. 2015. All rights reserved.
User manual
Rev. 2.1 — 10 December 2015
856 of 1441
NXP Semiconductors
UM10503
Chapter 28: LPC43xx/LPC43Sxx Ethernet
28.6.35 DMA Missed frame and buffer overflow counter register
The DMA maintains two counters to track the number of missed frames during reception.
This register reports the current value of the counter. The counter is used for diagnostic
purposes. Bits[15:0] indicate missed frames due to the host buffer being unavailable.
Bits[27:17] indicate missed frames due to buffer overflow conditions and runt frames
(good frames of less than 64 bytes) dropped by the MTL.
28.6.36 DMA Receive interrupt watchdog timer register
This register, when written with non-zero value, will enable the watchdog timer for RI (bit 6
in the DMA_STAT register).
Table 639. DMA Missed frame and buffer overflow counter register (DMA_MFRM_BUFOF,
address 0x4001 1020) bit description
Bit
Symbol
Description
Reset
value
Access
15:0
FMC
Number of frames missed
This register field can be read by the application (Read),
can be set to 1 by the Ethernet core on a certain internal
event (Self Set), and is automatically cleared to 0 on a
register read. A register write of 0 has no effect on 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. The counter is cleared when this register
is read with.
0
RO
16
OC
Overflow bit for missed frame counter
This register field can be read by the application (Read),
can be set to 1 by the Ethernet core on a certain internal
event (Self Set), and is automatically cleared to 0 on a
register read. A register write of 0 has no effect on this
field.
0
RO
27:17
FMA
Number of frames missed by the application
This register field can be read by the application (Read),
can be set to 1 by the Ethernet core on a certain internal
event (Self Set), and is automatically cleared to 0 on a
register read. A register write of 0 has no effect on this
field.
Indicates the number of frames missed by the application.
This counter is incremented each time the MTL asserts
the sideband signal. The counter is cleared when this
register is read.
0
RO
28
OF
Overflow bit for FIFO overflow counter
This register field can be read by the application (Read),
can be set to 1 by the Ethernet core on a certain internal
event (Self Set), and is automatically cleared to 0 on a
register read. A register write of 0 has no effect on this
field.
0
RO
31:29
-
Reserved
0
RO