Intel® IXP400 Software
Access-Layer Components: Feature Control (IxFeatureCtrl) API
Programmer’s Guide IXP400 Software Version 2.0 April 2005
Document Number: 252539, Revision: 007 185
12.3.2 Using the Feature Control Register Functions
The ixFeatureCtrlHwCapabilityRead( ) function utilizes the EXP_UNIT_FUSE_RESET register
for detecting host processor capabilities. A software structure for storing the changeable values for
each option is provided, and accessed using the ixFeatureCtrlRead ( ).
The mechanism which can simulate the disabling of components of the processor is a software
array, IxFeatureCtrlReg, that can be written with the ixFeatureCtrlWrite() function and read by
ixFeatureCtrlRead().
The IxFeatureCtrl component does not actually write values to the EXP_UNIT_FUSE_RESET
register.
Table 37. Feature Control Register Values (Sheet 1 of 2)
Bits Description
31:24 (Reserved)
23:22
Processor frequency (IXP46X product line only):
0x0 - 533 MHz
0x1 - 667 MHz
0x2 - 400 MHz
0x3 - 266 MHz
21 RSA Crypto Block coprocessor (IXP46X product line only)
20 NPE B Ethernet coprocessor 1-3 (IXP46X product line only)
19
IXP46X product line only
0 = NPE A Ethernet is enabled if Utopia bit is 1.
1 = NPE A Ethernet is disabled.
18 USB Host Coprocessor (IXP46X product line only)
17:16
UTOPIA PHY Limits.
32 PHYs: 0x0
16 PHYs: 0x1
8 PHYs: 0x2
4 PHYs: 0x3
15 ECC and 1588 Unit (IXP46X product line only)
14 PCI Controller
13 NPE C
12 NPE B
11 NPE A
10 Ethernet 1 Coprocessor (on NPE C)
9 Ethernet 0 Coprocessor (on NPE B)
8 UTOPIA Coprocessor
7 HSS Coprocessor
6 AAL Coprocessor
For bit 0 through 15, 18, 20-21 the following values apply:
0x0 — The hardware component exists and is not software disabled.
0x1 — The hardware component does not exist, or has been software disabled.