Figure 6-1. general memory interface configuration, 2 functional description, 1 sdram interface overview – Intel PXA26X User Manual

Page 192

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6-2

Intel® PXA26x Processor Family Developer’s Manual

Memory Controller

Figure 6-1. General Memory Interface Configuration

6.2

Functional Description

The processor has three different memory spaces: SDRAM, static memory, and card memory.

SDRAM has four partitions, static memory has six, and card space has two. When memory access
attempts to burst across the boundary between adjacent partitions, ensure that the configurations
for the partitions are identical. The configurations must be identical in every aspect, including
external bus width and burst length.

6.2.1

SDRAM Interface Overview

The processor supports the SDRAM interface, which supports four 16- or 32-bit-wide SDRAM
partitions. Each partition is allocated 64 Mbytes of the internal memory map, but the actual size of
each partition depends on the SDRAM configuration. The four partitions are divided into two

Memory

Controller

Interface

SDRAM Partition 0

SDRAM Partition 1

SDRAM Partition 2

SDRAM Partition 3

nSDCS<0>

nSDCS<1>

nSDCS<2>

nSDCS<3>

nCS<0>

nCS<1>

nCS<2>

nCS<3>

nCS<4>

nCS<5>

Static Bank 3

Static Bank 4

Static Bank 5

Buffers and

Transceivers

DQM[3:0]

nSDRAS, nSDCAS

SDCLK<2>, SDCKE<1>

SDCLK<1>, SDCKE<1>

SDCLK<0>,

MD[31:0]

MA[25:0]

Card Control

RDY

SDRAM Memory Interface
Up to 4 partitions of SDRAM
memory (16- or 32-bit wide)

16-bit PC Card Memory Interface
Up to 2-socket support.
Requires some
external buffering

Synchronous Static Memory Interface

Up to 6 banks of ROM, Flash,

NOTE:
Static Bank 0 is used by the internal

Static Memory or

Variable Latency I/O Interface

(16 or 32-bit wide)

(16 or 32-bit wide)

SRAM, Variable Latency I/O,

flash memory, except for PXA260

Static Bank 0

Static Bank 1

Static Bank 2

SDCKE<0>

Up to 4 banks of synchronous

static memory (nCS[3:0]).

NOTE:
Static Bank 0 must be populated by
“bootable” memory

MD[15:0]

MA[24:10]

(not supported for the

PXA210

processor)

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