PCI7510 datasheet(65/234 Pages) TI

65 / 234 page

3–25

an external clock is routed to the serial-interrupt state machine. Figure 3–15 is a signal diagram of the suspend

function.

RESET

GNT

SUSPEND

PCLK

RESETIN

SUSPENDIN

PCLKIN

External Terminals

Internal Signals

Figure 3–15. Signal Diagram of Suspend Function

3.9.7

Requirements for Suspend Mode

The suspend mode prevents the clearing of all register contents on the assertion of reset (PRST or GRST) which

would require the reconfiguration of the PCI7510 device by software. Asserting the SUSPEND signal places the PCI

outputs of the controller in a high-impedance state and gates the PCLK signal internally to the controller unless a PCI

transaction is currently in process (GNT is asserted). It is important that the PCI bus not be parked on the PCI7510

device when SUSPEND is asserted because the outputs are in a high-impedance state.

The GPIOs, MFUNC signals, and RI_OUT signal are all active during SUSPEND, unless they are disabled in the

appropriate PCI7510 registers.

3.9.8

Ring Indicate

The RI_OUT output is an important feature in power management, allowing a system to go into a suspended mode

and wake-up on modem rings and other card events. TI-designed flexibility permits this signal to fit wide platform

requirements. RI_OUT on the PCI7510 device can be asserted under any of the following conditions:

•

A 16-bit PC Card modem in a powered socket asserts RI to indicate to the system the presence of an

incoming call.

•

A powered down CardBus card asserts CSTSCHG (CBWAKE) requesting system and interface wake-up.

•

A powered CardBus card asserts CSTSCHG from the insertion/removal of cards or change in battery

voltage levels.

Figure 3–16 shows various enable bits for the PCI7510 RI_OUT function; however, it does not show the masking of

CSC events. See Table 3–12 for a detailed description of CSC interrupt masks and flags.

PCI7510 Datasheet(PDF) 65 Page - Texas Instruments