16.08.2012 Views

Intel® 945G/945GZ/945GC/ 945P/945PL Express Chipset Family ...

Intel® 945G/945GZ/945GC/ 945P/945PL Express Chipset Family ...

Intel® 945G/945GZ/945GC/ 945P/945PL Express Chipset Family ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Host-PCI <strong>Express</strong>* Bridge Registers (D1:F0) (<strong>Intel®</strong> 82<strong>945G</strong>/82<strong>945G</strong>C/82<strong>945P</strong>/82<strong>945P</strong>L Only)<br />

5 Host-PCI <strong>Express</strong>* Bridge<br />

Registers (D1:F0) (Intel ®<br />

82<strong>945G</strong>/82<strong>945G</strong>C/82<strong>945P</strong>/82<strong>945P</strong>L<br />

Only)<br />

Device 1 contains the controls associated with the PCI <strong>Express</strong> x16 root port that is the intended<br />

to attach as the point for external graphics. It is typically referred to as PCI <strong>Express</strong> (PCI <strong>Express</strong><br />

graphics) port. In addition, it also functions as the virtual PCI-to-PCI bridge. Table 5-1 provides<br />

an address map of the D1:F0 registers listed by address offset in ascending order. Section 5.1<br />

provides a detailed bit description of the registers.<br />

Warning: When reading the PCI <strong>Express</strong> "conceptual" registers such as this, you may not get a valid value<br />

unless the register value is stable.<br />

The PCI <strong>Express</strong>* Specification defines two types of reserved bits: Reserved and Preserved.<br />

� Reserved for future RW implementations; software must preserve value read for writes to<br />

bits.<br />

� Reserved and Zero: Reserved for future R/WC/S implementations; software must use 0 for<br />

writes to bits.<br />

Unless explicitly documented as Reserved and Zero, all bits marked as reserved are part of the<br />

Reserved and Preserved type, which have historically been the typical definition for Reserved.<br />

Note: Most (if not all) control bits in this device cannot be modified unless the link is down. Software is<br />

required to first Disable the link, then program the registers, and then re-enable the link (which<br />

will cause a full-retrain with the new settings).<br />

Table 5-1. Host-PCI <strong>Express</strong>* Graphics Bridge Register Address Map (D1:F0)<br />

Address<br />

Offset<br />

Symbol Register Name<br />

Default<br />

Value<br />

Access<br />

00–01h VID1 Vendor Identification 8086h RO<br />

02–03h DID1 Device Identification 2771h RO<br />

04–05h PCICMD1 PCI Command 0000h RO, R/W<br />

06–07h PCISTS1 PCI Status 0010h RO, R/W<br />

08h RID1 Revision Identification See register<br />

description<br />

09–0Bh CC1 Class Code 060400h RO<br />

0Ch CL1 Cache Line Size 00h R/W<br />

0Dh — Reserved — —<br />

0Eh HDR1 Header Type 01h RO<br />

Intel ® 82<strong>945G</strong>/82<strong>945G</strong>/82<strong>945G</strong>C GMCH and 82<strong>945P</strong>/82<strong>945P</strong>L MCH Datasheet 109<br />

RO

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!