Texas Instruments PCI445X manual Interrupt Signaling Interface, Miscellaneous Signals

System Implementation

If the third ZV source is not implemented, ZVPCLK and ZVSTAT are not required. To support ZV audio, an audio codec device is required for L and R sound decoding.

1.3.3Interrupt Signaling Interface

￿Serialized Interrupt Interface

The serialized interrupt (ISA and PCI) interface is a single-line interface, IRQSER. A pullup resistor is required on this terminal. The signal is synchronous to PCLK, so PCLK is a required signal. Please remember that SUSPEND gates PCLK internally. Usually this signal is connected to the south bridge (ex., PIIX4). The IRQSER signal is sharable with other devices.

￿Parallel PCI Interrupt

See Section 1.2.2, PCI Bus Interface.

1.3.4Miscellaneous Signals

1.3.4.1SUSPEND

The SUSPEND signal gates the PRST and G_RST signals from the PCI445X device. SUSPEND also gates PCLK inside the PCI445X device in order to minimize power consumption. Gating PCLK makes the IRQSER state machine stop until SUSPEND is deasserted. Two requirements for implementing suspend mode are that the PCI bus must not be parked on the PCI445X device and IRQSER signaling is not proceeding when SUSPEND is asserted.

1.3.4.2RI_OUT and PME

RI_OUT can be programmed on the RI_OUT/PME or MFUNC7 terminal. PME can be programmed only on the RI_OUT/PME terminal. To support both RI_OUT and PME in a system, the RI_OUT/PME terminal must be programmed as PME. These signals are usually connected to the south bridge (ex., PIIX4) or an embedded controller (EC). Buffers of the RI_OUT/PME type are open-drain; therefore, a pullup resistor is required on this terminal.

1.3.4.3SPKROUT

SPKROUT is a dedicated terminal and it is usually mixed to PC sound, and connected to a sound device.

1.3.4.4Activity LEDs

Activity LEDs can be programmed on MFUNC terminals. These signals are active-high and driven for 64 ms duration.

1.3.4.5Distributed DMA (DDMA)

The PCI445X device supports both PC/PCI (centralized) DMA and a distributed DMA slave engine for 16-bit PC Card DMA support.

PCI445X Device 1-15