6.5 Socket Control Register
This register provides control of the voltages applied to the socket V and V . The PCI6x21/PCI6x11 controller
PP
CC
ensures that the socket is powered up only at acceptable voltages when a CardBus card is inserted. See Table 6−6
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
Type
Default
Socket control
R
0
R
0
R
0
R
0
R
0
R
0
R
0
R
0
R
0
R
0
R
0
R
0
R
0
R
0
R
0
R
0
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
Type
Default
Socket control
R
0
R
0
R
0
R
0
R
0
R
0
RW
0
R
0
RW
0
RW
0
RW
0
RW
0
R
0
RW
0
RW
0
RW
0
Register:
Offset:
Type:
Socket control
CardBus Socket Address + 10h
Read-only, Read/Write
0000 0000h
Default:
Table 6−6. Socket Control Register Description
BIT
31−11
10
SIGNAL
TYPE
FUNCTION
RSVD
RSVD
RSVD
R
R
R
These bits return 0s when read.
This bit returns 1 when read.
These bits return 0s when read.
9−8
This bit controls how the CardBus clock run state machine decides when to stop the CardBus clock
to the CardBus card:
0 = The CardBus CLKRUN protocol can only attempt to stop/slow the CaredBus clock if the
sockethas been idle for 8 clocks and the PCI CLKRUN protocol is preparing to stop/slow the
PCI bus clock.
7
STOPCLK
RW
1 = The CardBus CLKRUN protocol can only attempt to stop/slow the CaredBus clock if the
socket has been idle for 8 clocks, regardless of the state of the PCI CLKRUN signal.
V
CC
control. These bits are used to request card V changes.
CC
000 = Request power off (default)
001 = Reserved
100 = Request V
101 = Request V
110 = Reserved
111 = Reserved
= X.X V
= Y.Y V
CC
CC
6−4 †
3
VCCCTRL
RSVD
RW
R
010 = Request V
011 = Request V
= 5 V
= 3.3 V
CC
CC
This bit returns 0 when read.
control. These bits are used to request card V
V
changes.
PP
PP
000 = Request power off (default)
100 = Request V
101 = Request V
110 = Reserved
111 = Reserved
= X.X V
= Y.Y V
PP
PP
2−0 †
VPPCTRL
RW
001 = Request V
010 = Request V
011 = Request V
= 12 V
= 5 V
= 3.3 V
PP
PP
PP
†
One or more bits in the register are PME context bits and can be cleared only by the assertion of GRST when PME is enabled. If PME is not
enabled, then this bit is cleared by the assertion of PRST or GRST.
6−7