Filter
Top Products
Intel
®
IXP400 Software
Access-Layer Components: Feature Control (IxFeatureCtrl) API
April 2005 IXP400 Software Version 2.0 Programmer’s Guide
184 Document Number: 252539, Revision: 007
stepping. For the IXP42X product line, this register is used to determine the maximum core
clock speed.
Note: CP15, Register 0 is read-only.
• EXP_UNIT_FUSE_RESET register in the Expansion Bus Controller - A software copy of this
register, called the
Feature Control Register, can be created and manipulated by this software
component.
The Feature Control Register is a structure which contains information on which components
are physically available on the processor. The detectable capabilities include the existence of
key coprocessors or peripherals (PCI controller, AES coprocessor, NPEs, etc.). The
ixFeatureCtrlHwCapabilityRead( ) function utilizes this register for detecting host processor
capabilities.
Note: The only way to detect the core frequency on the IXP46X product line is to use the
ixFeatureCtrlHwCapabilityRead( ) and check bits 22 and 23.
12.3.1 Using the Product ID-Related Functions
The functions ixFeatureCtrlDeviceRead ( ) and ixFeatureCtrlProductIdRead( ) return values
based upon the CP15 register discussed above. ixFeatureCtrlProductIdRead() returns the entire 32-
bit value, as documented below. ixFeatureCtrlDeviceRead() only returns an indication of the
processor product line; the IXP46X product line or IXP42X product line.
Table 36. Product ID Values
Bits Description
31:28 Reserved. Value: 0x6
27:24 Reserved. Value: 0x9
23:20 Reserved. Value: 0x0
19:16 Reserved. Value: 0x5
15:12 Reserved. Value: 0x4
11:9
Device ID.
IXP42X - 0x0
IXP46X - 0x1
8:4
Maximum Achievable Intel XScale
®
Core Frequency
for the IXP42X product line only.
533 MHz — 0x1C
400 MHz — 0x1D
266 Mhz — 0x1F
For the IXP46X product line, the value will be 0x00
.
3:0
Si Stepping ID.
A-step — 0x0
B-step — 0x1