26 emac statistic registers – Rainbow Electronics AT91CAP9S250A User Manual
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6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
42.5.26
EMAC Statistic Registers
These registers reset to zero on a read and stick at all ones when they count to their maximum value. They should be read
frequently enough to prevent loss of data. The receive statistics registers are only incremented when the receive enable bit
is set in the network control register. To write to these registers, bit 7 must be set in the network control register. The statis-
tics register block contains the following registers.
42.5.26.1
Pause Frames Received Register
Register Name:
EMAC_PFR
Access Type:
Read/Write
• FROK: Pause Frames received OK
A 16-bit register counting the number of good pause frames received. A good frame has a length of 64 to 1518 (1536 if bit
8 set in network configuration register) and has no FCS, alignment or receive symbol errors.
42.5.26.2
Frames Transmitted OK Register
Register Name:
EMAC_FTO
Access Type:
Read/Write
• FTOK: Frames Transmitted OK
A 24-bit register counting the number of frames successfully transmitted, i.e., no underrun and not too many retries.
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
FROK
7
6
5
4
3
2
1
0
FROK
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
FTOK
15
14
13
12
11
10
9
8
FTOK
7
6
5
4
3
2
1
0
FTOK