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NXP Semiconductors
PNX15xx/952x Series
Volume 1 of 1
Chapter 3: System On Chip Resources
PNX15XX_PNX952X_SER_N_4
NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 4.0 — 03 December 2007
3-110
Before going into the details of the three different views the following generic rules
should be noted:
The three views must be consistent. For example, it is not allowed to have a
different DRAM aperture location for the TM3260 CPU and the PCI module.
The apertures are “naturally aligned”. For example a 32-Megabyte aperture has a
starting address that is a multiple of 32 Megabytes.
Each aperture can be located anywhere in the 32-bit addressing space.
All the modules in the PNX15xx/952x Series SOC sees the same memory map,
i.e. an address represents an unique location for all the modules.
These apertures need to be programmed at boot time or by the host before the
system can be operational. The internal boot scripts have pre-dened values for
2.1 The PCI View
The PCI module provides three different apertures to the external PCI bus masters:
the MMIO aperture, used to access all the internal PNX15xx/952x Series
the DRAM aperture, used to access to the main memory of PNX15xx/952x
Series.
the XIO aperture, used by TM3260 to access low speed slave devices like Flash
memories or IDE disk drives.
Any supported request on the PCI bus that falls outside of these three apertures is
discarded by the PCI module and therefore does not interfere with the PNX15xx/952x
Series system.
In addition PCI transactions to the XIO aperture from external PCI agents are
discarded.
Figure 2 presents the memory map seen by the PCI module and the remaining of the
PNX15xx/952x Series system. The apertures can be placed in any order with respect
to each other.
The aperture locations is programmed by the host CPU.
The aperture sizes can be programmed at boot time via some GPIO/BOOT_MODE[]
CPU using PCI conguration cycles.
The MMIO aperture is starting at the address contained in the BASE_14 PCI
conguration space register.
The DRAM aperture is starting at the address contained in the BASE_10 PCI
conguration space register.
The XIO aperture is starting at the address contained in the BASE_18 PCI
conguration space register.