![](http://datasheet.mmic.net.cn/330000/PCI6421_datasheet_16443878/PCI6421_119.png)
57
5.3
ExCA Power Control Register
This register provides PC Card power control. Bit 7 of this register enables the 16-bit outputs on the socket interface,
and can be used for power management in 16-bit PC Card applications. See Table 55 for a complete description
of the register contents.
Bit
7
6
5
4
3
2
1
0
Name
ExCA power control
Type
RW
R
R
RW
RW
R
RW
RW
Default
0
0
0
0
0
0
0
0
Register:
Offset:
ExCA power control
CardBus Socket Address + 802h:
Card A ExCA Offset 02h
Card B ExCA Offset 42h
Type:
Default:
Read-only, Read/Write
00h
Table 54. ExCA Power Control Register Description—82365SL Support
BIT
SIGNAL
TYPE
FUNCTION
7
COE
RW
Card output enable. Bit 7 controls the state of all of the 16-bit outputs on the PCI6x21/PCI6x11 controller.
This bit is encoded as:
0 = 16-bit PC Card outputs disabled (default)
1 = 16-bit PC Card outputs enabled
6
RSVD
R
Reserved. Bit 6 returns 0 when read.
5
AUTOPWRSWEN
RW
Auto power switch enable.
0 = Automatic socket power switching based on card detects is disabled.
1 = Automatic socket power switching based on card detects is enabled.
4
CAPWREN
RW
PC Card power enable.
0 = VCC = No connection
1 = VCC is enabled and controlled by bit 2 (EXCAPOWER) of the system control register
(PCI offset 80h, see Section 4.29).
32
RSVD
R
Reserved. Bits 3 and 2 return 0s when read.
10
EXCAVPP
RW
PC Card VPP power control. Bits 1 and 0 are used to request changes to card VPP. The PCI6x21/PCI6x11
controller ignores this field unless VCC to the socket is enabled. This field is encoded as:
00 = No connection (default)
10 = 12 V
01 = VCC
11 = Reserved
One or more bits in this register are 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.
Table 55. ExCA Power Control Register Description—82365SL-DF Support
BIT
SIGNAL
TYPE
FUNCTION
7
COE
RW
Card output enable. This bit controls the state of all of the 16-bit outputs on the PCI6x21/PCI6x11 controller.
This bit is encoded as:
0 = 16-bit PC Card outputs are disabled (default).
1 = 16-bit PC Card outputs are enabled.
65
RSVD
R
Reserved. These bits return 0s when read. Writes have no effect.
43
EXCAVCC
RW
VCC. These bits are used to request changes to card VCC. This field is encoded as:
00 = 0 V (default)
01 = 0 V reserved
10 = 5 V
11 = 3.3 V
2
RSVD
R
This bit returns 0 when read. A write has no effect.
10
EXCAVPP
RW
VPP. These bits are used to request changes to card VPP. The PCI6x21/PCI6x11 controller ignores this
field unless VCC to the socket is enabled (i.e., 5 Vdc or 3.3 Vdc). This field is encoded as:
00 = 0 V (default)
10 = 12 V
01 = VCC
11 = 0 V reserved
This bit is 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.