Texas Instruments Dual/Single Socket CardBus and UntraMedia Controller PCI7621 - Manual (Page 135)

5−7
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 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: ExCA power control
Offset: CardBus Socket Address + 802h: Card A ExCA Offset 02h
Card B ExCA Offset 42h
Type: Read-only, Read/Write
Default: 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 PCI7x21/PCI7x11 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).
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 PCI7x21/PCI7x11
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 5−5. 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 PCI7x21/PCI7x11 controller.
This bit is encoded as:
0 = 16-bit PC Card outputs are disabled (default).
1 = 16-bit PC Card outputs are enabled.
6−5 RSVD R Reserved. These bits return 0s when read. Writes have no effect.
4−3 † EXCAVCC RW
VCC. These bits are used to request changes to card VCC. This field is encoded as:
00 = 0 V (default) 10 = 5 V
01 = 0 V reserved 11 = 3.3 V
2 RSVD R This bit returns 0 when read. A write has no effect.
1−0 † EXCAVPP RW
VPP. These bits are used to request changes to card VPP. The PCI7x21/PCI7x11 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.