dmagrp_missed_frame_and_buffer_overflow_counter
Register 8 (Missed Frame and Buffer Overflow Counter Register)
The DMA maintains two counters to track the number of frames missed during reception. This register reports the current value of the counter. The counter is used for diagnostic purposes. Bits[15:0] indicate missed frames because of the host buffer being unavailable. Bits[27:17] indicate missed frames because of buffer overflow conditions (MTL and MAC) and runt frames (good frames of less than 64 bytes) dropped by the MTL.
Module Instance | Base Address | Register Address |
---|---|---|
i_emac_emac0 | 0xFF800000 | 0xFF801020 |
i_emac_emac1 | 0xFF802000 | 0xFF803020 |
i_emac_emac2 | 0xFF804000 | 0xFF805020 |
Size: 32
Offset: 0x1020
Access: RO
Important: The value of a reserved bit must be maintained in software. When you modify registers containing reserved bit fields, you must use a read-modify-write operation to preserve state and prevent indeterminate system behavior.
Bit Fields | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 |
reserved_31_29 RO 0x0 |
ovfcntovf RO 0x0 |
ovffrmcnt RO 0x0 |
miscntovf RO 0x0 |
||||||||||||
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
misfrmcnt RO 0x0 |
dmagrp_missed_frame_and_buffer_overflow_counter Fields
Bit | Name | Description | Access | Reset |
---|---|---|---|---|
31:29 | reserved_31_29 |
Reserved |
RO | 0x0 |
28 | ovfcntovf |
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 that the rollover happened. |
RO | 0x0 |
27:17 | ovffrmcnt |
Overflow Frame Counter This field indicates the number of frames missed by the application. This counter is incremented each time the MTL FIFO overflows. The counter is cleared when this register is read with mci_be_i[2] at 1'b1. |
RO | 0x0 |
16 | miscntovf |
Overflow Bit for Missed Frame Counter This bit is set every time Missed Frame Counter (Bits[15:0]) overflows, that is, 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. |
RO | 0x0 |
15:0 | misfrmcnt |
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. The counter is cleared when this register is read with mci_be_i[0] at 1'b1. |
RO | 0x0 |