![](http://datasheet.mmic.net.cn/330000/PCI4515_datasheet_16443874/PCI4515_178.png)
828
8.31 Link Control Register
The link control set/clear register provides the control flags that enable and configure the link core protocol portions
of the PCI4515 controller. It contains controls for the receiver and cycle timer. See Table 823 for a complete
description of the register contents.
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Name
Link control
Type
R
R
R
R
R
R
R
R
R
RSC
RSCU
RSC
R
R
R
R
Default
0
0
0
0
0
0
0
0
0
X
X
X
0
0
0
0
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
Link control
Type
R
R
R
R
R
RSC
RSC
R
R
RS
R
R
R
R
R
R
Default
0
0
0
0
0
X
X
0
0
0
0
0
0
0
0
0
Register:
Offset:
Link control
E0h
E4h
Read/Set/Clear/Update, Read/Set/Clear, Read-only
00X0 0X00h
set register
clear register
Type:
Default:
Table 823. Link Control Register Description
BIT
FIELD NAME
TYPE
DESCRIPTION
3123
RSVD
R
Reserved. Bits 3123 return 0s when read.
22
cycleSource
RSC
When bit 22 is set to 1, the cycle timer uses an external source (CYCLEIN) to determine when to roll
over the cycle timer. When this bit is cleared, the cycle timer rolls over when the timer reaches
3072 cycles of the 24.576-MHz clock (125
μ
s).
When bit 21 is set to 1, the PCI4515 controller is root and it generates a cycle start packet every time
the cycle timer rolls over, based on the setting of bit 22 (cycleSource). When bit 21 is cleared, the
OHCI-Lynx
accepts received cycle start packets to maintain synchronization with the node which
is sending them. Bit 21 is automatically cleared when bit 25 (cycleTooLong) in the interrupt event
register at OHCI offset 80h/84h (see Section 8.21) is set to 1. Bit 21 cannot be set to 1 until bit 25
(cycleTooLong) is cleared.
21
cycleMaster
RSCU
20
CycleTimerEnable
RSC
When bit 20 is set to 1, the cycle timer offset counts cycles of the 24.576-MHz clock and rolls over
at the appropriate time, based on the settings of the above bits. When this bit is cleared, the cycle
timer offset does not count.
1911
RSVD
R
Reserved. Bits 1911 return 0s when read.
10
RcvPhyPkt
RSC
When bit 10 is set to 1, the receiver accepts incoming PHY packets into the AR request context if
the AR request context is enabled. This bit does not control receipt of self-identification packets.
9
RcvSelfID
RSC
When bit 9 is set to 1, the receiver accepts incoming self-identification packets. Before setting this
bit to 1, software must ensure that the self-ID buffer pointer register contains a valid address.
87
RSVD
R
Reserved. Bits 8 and 7 return 0s when read.
6
tag1SyncFilterLock
RS
When bit 6 is set to 1, bit 6 (tag1SyncFilter) in the isochronous receive context match register (see
Section 8.46) is set to 1 for all isochronous receive contexts. When bit 6 is cleared, bit 6
(tag1SyncFilter) in the isochronous receive context match register has read/write access. This bit is
cleared when GRST is asserted.
50
RSVD
R
Reserved. Bits 50 return 0s when read.
This bit is cleared only by the assertion of GRST.