Texas Instruments TMS320C645x DSP Benutzerhandbuch
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5.39 Back Off Test Register (BOFFTEST)
EMAC Port Registers
The back off test register (BOFFTEST) is shown in
and described in
Figure 67. Back Off Random Number Generator Test Register (BOFFTEST)
31
26
25
16
Reserved
RNDNUM
R-0
R-0
15
12
11
10
9
0
COLLCOUNT
Reserved
TXBACKOFF
R-0
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 67. Back Off Test Register (BOFFTEST) Field Descriptions
Bit
Field
Value
Description
31-26
Reserved
0
Reserved
25-16
RNDNUM
Back off random number generator. This field allows the Back off Random Number Generator to be
read. Reading this field returns the generator's current value. The value is reset to zero and begins
counting on the clock after the de-assertion of reset.
read. Reading this field returns the generator's current value. The value is reset to zero and begins
counting on the clock after the de-assertion of reset.
15-12
COLLCOUNT
Collision count. These bits indicate the number of collisions the current frame has experienced.
11-10
Reserved
0
Reserved
9-0
TXBACKOFF
Back off count. This field allows the current value of the back off counter to be observed for test
purposes. This field is loaded automatically according to the back off algorithm, and is decremented
by one for each slot time after the collision.
purposes. This field is loaded automatically according to the back off algorithm, and is decremented
by one for each slot time after the collision.
SPRU975B – August 2006
Ethernet Media Access Controller (EMAC)/Management Data Input/Output (MDIO)
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