
5
–
7
5.3
ExCA Power Control Register
The ExCA power control register provides PC Card power control. Bit 7 (COE) of this register controls the 16-bit output
enables on the socket interface, and can be used for power management in 16-bit PC Card applications. See
Table 5
–
4 and Table 5
–
5 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 5
–
4. 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 PCI1520. 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).
3
–
2
RSVD
R
Reserved. Bits 3 and 2 return 0s when read.
1
–
0
EXCAVPP
RW
PC Card VPP power control. Bits 1 and 0 are used to request changes to card VPP. The PCI1520 ignores
this field unless VCC to the socket is enabled. This field is encoded as:
00 = No connection (default)
01 = VCC
10 = 12 V
11 = Reserved
Table 5
–
5. ExCA Power Control Register Description
—
82365SL-DF 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 PCI1520. This bit is encoded as:
0 = 16-bit PC Card outputs disabled (default)
1 = 16-bit PC Card outputs enabled
6
–
5
RSVD
R
Reserved. Bits 6 and 5 return 0s when read.
4
–
3
EXCAVCC
RW
VCC. Bits 4 and 3 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
Reserved. Bit 2 returns 0 when read.
1
–
0
EXCAVPP
RW
VPP. Bits 1 and 0 are used to request changes to card VPP. The PCI1520 ignores this field unless VCC to
the socket is enabled. This field is encoded as:
00 = No connection (default)
01 = VCC
10 = 12 V
11 = Reserved