Datasheet

Register and Memory Mapping
Intel
®
Atom™ Processor E6xx Series Datasheet
53
5.0 Register and Memory Mapping
This chapter describes the I/O and memory map settings for the Intel
®
Atom™
Processor E6xx Series in the MCP.
5.1 Address Map
The Intel
®
Atom™ Processor E6xx Series contains registers that are located in the
processor’s memory and I/O space. It also contains sets of PCI configuration registers
that are located in a separate configuration space.
5.2 Introduction
The Intel
®
Atom™ Processor E6xx Series contains two sets of software accessible
registers accessed via the host processor I/O address space: Control registers and
internal configuration registers.
Table 35. Register Access Types and Definitions
Access Type Meaning Description
RO Read Only
In some cases, if a register is read only, writes to this
register location have no effect. However, in other cases,
two separate registers are located at the same location
where a read accesses one of the registers and a write
accesses the other register. See the I/O and memory map
tables for details.
WO Write Only
In some cases, if a register is write only, reads to this
register location have no effect. However, in other cases,
two separate registers are located at the same location
where a read accesses one of the registers and a write
accesses the other register. See the I/O and memory map
tables for details.
R/W Read/Write A register with this attribute can be read and written.
R/WC Read/Write Clear
A register bit with this attribute can be read and written.
However, a write of 1 clears (sets to 0) the corresponding
bit and a write of 0 has no effect.
R/WO Read/Write-Once
A register bit with this attribute can be written only once
after power up. After the first write, the bit becomes read
only.
R/WLO
Read/Write, Lock-
Once
A register bit with this attribute can be written to the non-
locked value multiple times, but to the locked value only
once. After the locked value has been written, the bit
becomes read only.
Default Default
When the processor is reset, it sets its registers to
predetermined default states. The default state represents
the minimum functionality feature set required to
successfully bring up the system. Hence, it does not
represent the optimal system configuration. It is the
responsibility of the system initialization software to
determine configuration, operating parameters, and
optional system features that are applicable, and to
program the processor registers accordingly.