Intel
®
81341 and 81342—Introduction
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
54
Order Number: 315037-002US
1.6.3
Specifying Bit and Signal Values
The terms set and clear in this specification refer to bit values in register and data
structures. When a bit is set, its value is 1; when the bit is clear, its value is 0. Likewise,
setting a bit means giving it a value of 1 and clearing a bit means giving it a value of 0.
The terms assert and deassert refer to the logically active or inactive value of a signal
or bit, respectively.
1.6.4
Signal Name Conventions
All signal names use the PCI signal name convention of using the “#” symbol at the end
of a signal name to indicate that the signal’s active state occurs when it is at a low
voltage. The absence of the “#” symbol indicates that the signal’s active state occurs
when it is at a high voltage.
1.6.5
Terminology
To aid the discussion of the 81341 and 81342 architecture, the following terminology is
used:
Downstream
At or toward a PCI bus with a higher number (after
configuration)
DWORD
32-bit data word
QWORD
64-bit data word
word
32-bit data word
Host processor
Processor located upstream from the 81341 and 81342
Local processor
Intel XScale
®
processor within the 81341 and 81342
Local bus
81341 and 81342 Internal Bus
Local memory
Memory subsystem on the Intel XScale
®
processor DDR SDRAM
or Peripheral Bus Interface busses
Upstream
At or toward a PCI bus with a lower number (after configuration)