Technical information

7-28
AIC-6915 Ethernet LAN Controller Programmer’s Manual
TimersControl Register
Type: R/W
Internal Registers Subgroup: Ethernet Functional Registers
Byte Address: 74h - 77h
Table 7-40. TimersControl Register
Bit(s) rw
Reset
value Description/Function
31 r/w 0
EarlyRxQ1IntDelayDisable:
When set, the interrupt masking timer
has no effect on
EarlyRxQ1Int
.
30 r/w 0
RxQ1DoneIntDelayDisable:
When set, the interrupt masking timer
has no effect on
RxQ1DoneInt
.
29 r/w 0
EarlyRxQ2IntDelayDisable:
When set, the interrupt masking timer
has no effect on
EarlyRxQ2Int
.
28 r/w 0
RxQ2DoneIntDelayDisable:
When set, the interrupt masking timer
has no effect on
RxQ2DoneInt
.
27 r 0
Reserved:
Always reads 0.
26 r/w 0
TimeStampResolution:
Specifies the resolution of the time stamp
recorded in the long format transmit completion descriptor. The
recorded time stamp is a 13-bit number equal to
CurrentTime[12:0]
if
TimeStampResolution
is reset (0), otherwise it is equal to
CurrentTime[20:8]
. The long-format receive completion descriptors
always include the full 32-bit CurrentTime.
25 r/w 0
GeneralTimerResolution:
Specifies the resolution of
GeneralTimer,
that controls the spacing of
GeneralTimerInt
. When the bit is
cleared the timer has a resolution of 2
4
TimerClock
periods (12.8
µ
s).
When the bit is set the resolution is 2
9
TimerClock
periods (0.4096
ms).
24 r/w 0
OneShotMode:
Specifies the
GeneralTimer
operation mode. If the
bit is set, only one interrupt is produced when the timer reaches its
terminal count, else the
GeneralTimer
continuously produces
interrupts every period as defined by
GeneralTimerResolution
and
GeneralTimerInterval
bits.
23:16 r/w 0
GeneralTimerInterval:
Specifies the spacing between two
consecutive assertions of the interrupt status bit,
GeneralTimerInt
.
A default value ‘0’ does not delay the assertion of the interrupt
status bit. If the
TimerClock
period is ~0.8
µ
S and the
GeneralTimer
is running at high resolution mode (
GeneralTimerResolution=1
),
the interrupt spacing range is: 12.8
µ
s - 3.264 ms. For the low
resolution mode the range is: 0.4096 mS - 104.8 ms. The general
timer starts when this field is not 0.
15 r/w 0
TxFrameCompleteIntDelayDisable:
When set, the interrupt
masking timer has no effect on
TxFrameCompleteInt
.
14 r/w 0
TxQueueDoneIntDelayDisable:
When set, the interrupt masking
timer has no effect on
TxQueueDoneInt
.
13 r/w 0
TxDmaDoneIntDelayDisable:
When set, the interrupt masking
timer has no effect on
TxDmaDoneInt
.