EMAC Registers
1031
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Ethernet Controller
15.6.62 EMACMFBOC Register (Offset = 0xC20) [reset = 0x0]
Ethernet MAC Missed Frame and Buffer Overflow Counter (EMACMFBOC)
The DMA maintains two counters to track the number of frames missed during reception. This register
reports the current value of the counters. The counter is used for diagnostic purposes. The MISFRMCNT
field indicates missed frames because of the host buffer being unavailable. The OVFFRMCNT field
indicates missed frames because of buffer overflow conditions (MTL and MAC) and runt frames (good
frames of less than 64 bytes) dropped by the MTL.
EMACMFBOC is shown in
and described in
Return to
Figure 15-77. EMACMFBOC Register
31
30
29
28
27
26
25
24
RESERVED
OVFCNTOVF
OVFFRMCNT
R-0x0
R-0x0
R-0x0
23
22
21
20
19
18
17
16
OVFFRMCNT
MISCNTOVF
R-0x0
R-0x0
15
14
13
12
11
10
9
8
MISFRMCNT
R-0x0
7
6
5
4
3
2
1
0
MISFRMCNT
R-0x0
Table 15-87. EMACMFBOC Register Field Descriptions
Bit
Field
Type
Reset
Description
31-29
RESERVED
R
0x0
28
OVFCNTOVF
R
0x0
Overflow Bit for FIFO Overflow Counter. This bit is set every time the
overflow frame counter (bits [27:17]) overflows; that is, the RX FIFO
overflows with the overflow frame counter at maximum value. In
such a scenario, the overflow frame counter is reset to all zeros and
this bit indicates the rollover happened.
27-17
OVFFRMCNT
R
0x0
Overflow Frame Counter. This field indicates the number of frames
missed by the application. This counter is incremented each time the
TX/RX Controller indicates overflow. This counter is cleared when
the TX/RX Controller accepts data.
16
MISCNTOVF
R
0x0
Overflow bit for Missed Frame Counter. This bit is set every time the
Missed Frame Counter (bits [15:0]) overflows; which means the DMA
discards an incoming frame because of the Host Receive Buffer
being unavailable with the missed frame counter at maximum value.
In such a scenario, the Missed Frame Counter is reset to all zeros
and this bit indicates that the rollover happened.
15-0
MISFRMCNT
R
0x0
Missed Frame Counter. This field indicates the number of frames
missed by the controller because of the Host Receive Buffer being
unavailable. This counter is incremented each time the DMA
discards an incoming frame. This counter is cleared when the DMA
accepts frames.