LH79524/LH79525 User’s Guide
Ethernet MAC Controller
Version 1.0
6-29
6.3.2.7 Receive Status Register (RXSTATUS)
Read this register to obtain details of the status of a receive. Once read, individual bits may
be cleared by writing 1 to them. It is not possible to set a bit to 1 by writing to the register
.
Table 6-18. RXSTATUS Register
BIT
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FIELD
///
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
TYPE
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FIELD
///
RXCOVE
R
RUN
FR
MR
EC
B
U
FNOTAVAIL
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
TYPE
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RW
RW
RW
ADDR
0xFF 0x20
Table 6-19. RXSTATUS Fields
BITS
NAME
FUNCTION
31:3
///
Reserved
Reading returns 0. Write the reset value.
2
RXCOVERRUN
Receive Overrun
The DMA Block was unable to store the receive frame to
memory. Either because the AHB bus was not granted in time or because a ‘Not
OK’ response was returned. The buffer will be recovered if this happens.
Read:
1 = DMA unable to store receive frame
0 = Normal operation
Write:
1 = Reset bit to 0
0 = No effect
1
FRMREC
Frame Received
Indicates that one or more frames have been received and
placed in memory.
Read:
1 = One or more frames have been received and placed in memory
0 = No received frames
Write:
1 = Reset bit to 0
0 = No effect
0
BUFNOTAVAIL
Buffer Not Available
An attempt was made to get a new buffer and the pointer
indicated that it was owned by the processor. The DMA will reread the pointer each
time a new frame starts until a valid pointer is found. This bit will be 1 at each attempt
that fails even if it has not had a successful pointer read since it has been cleared.
Read:
1 = Buffer not available
0 = Buffer available
Write:
1 = Reset bit to 0
0 = No effect