PCI1221 Datasheet, PDF (42/123 Pages) Texas Instruments – PC CARD CONTROLLERS

PCI1221 GHK/PDV
PC CARD CONTROLLERS
SCPS042 – JULY 1998
ring indicate (continued)
PC Card
Socket 0
PC Card
Socket 1
RI_OUT Function
CSTSMASK
Card
I/F
CSC
RINGEN
RI
CDRESUME
CSC
CSTSMASK
Card
I/F
CSC
RINGEN
RI
CDRESUME
CSC
RIENB
RI_OUT
Figure 19. RI_OUT Functional Diagram
RI from the 16-bit PC Card interface is masked by the ExCA control bit RINGEN in the interrupt and general
control register. This is programmed on a per-socket basis and is only applicable when a 16-bit card is powered
in the socket.
The CBWAKE signaling to RI_OUT is enabled through the same mask as the CSC event for CSTSCHG. The
mask bit, CSTSMASK, is programmed through the socket mask register in the CardBus socket registers.
PCI power management (PCIPM)
The PCI power-management (PCIPM) specification establishes the infrastructure required to let the operating
system control the power of PCI functions. This is done by defining a standard PCI interface and operations to
manage the power of PCI functions on the bus. The PCI bus and the PCI functions can be assigned one of four
software-visible power-management states that result in varying levels of power savings.
The four power-management states of PCI functions are:
D D0 - Fully-on state
D D1 and D2 - Intermediate states
D D3 - Off state
Similarly, bus power states of the PCI bus are B0-B3. The bus power states B0-B3 are derived from the device
power state of the originating bridge device.
For the operating system (OS) to power manage the device power states on the PCI bus, the PCI function should
support four power-management operations. These operations are:
D Capabilities reporting
D Power status reporting
D Setting the power state
D System wake up
42
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265