4Accessing the 4538 on the PCI Side

PowerSpan Configuration by the PCI Host

4

Several elements of the PowerSpan are automatically configured at power-up by the hardware, or by the PowerQUICC II. However, some PCI-specific settings have to be done by the PCI host.

PCI Configuration

The card is identified through its Interphase Vendor ID (0x107E) and its PCI device ID (0x9070). Its PCI configuration is set up by the PCI host at its power-on or by the “high availability” operating system if the 4538 has been hot inserted.

Interrupt Pin Configuration

The set up of the PowerSpan Interrupt Map registers is normally done by the PowerQUICC

IIwhen it boots, so they should not need to be reconfigured, except if the card has not yet received a valid boot firmware.

PCI-to-Local Window Configuration

When accessing through a PowerSpan PCI-to-local window, this window must have been enabled in the I2C serial EEPROM, in order to allow the CompactPCI host to detect it at system power-on or after hot insertion of the board, and map it in the PCI space.

The corresponding PowerSpan register PCI Target Image Control Register must also have been initialized with the Image Enable bit set (IMG_EN=1) and the address translation mechanism enabled (TA_EN=1).

Controlling the 4538 Hardware and Software Resets

PowerSpan interrupt pins –INT2 and –INT3 are used as output ports to control the MPC8260 hardware reset signal –HRESET and software reset signal –SRESET respectively. They are conventionally associated with doorbell bits 4 and 5 respectively. The PowerSpan Interrupt Map registers must have been correctly initialized before (see PowerSpan Configuration by the PCI Host on page 87).

During a power-up sequence, –HRESET and –SRESET are first activated and then deactivated once the PCI bus reset signal is deactivated. This allows the PowerQUICC II to boot without any host intervention, just after the end of the PCI reset.

4538 Hardware Reference Manual

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