Intel PXA255 Developer's Manual page 6

Contents
6.2.1 SDRAM Interface Overview..................................................................................6-2
6.2.2 Static Memory Interface / Variable Latency I/O Interface .....................................6-3
6.2.3 16-Bit PC Card / Compact Flash Interface ...........................................................6-4
6.3 Memory System Examples ................................................................................................6-4
6.4 Memory Accesses .............................................................................................................6-7
6.4.1 Reads and Writes .................................................................................................6-8
6.4.2 Aborts and Nonexistent Memory ..........................................................................6-8
6.5 Synchronous DRAM Memory Interface .............................................................................6-8
6.5.1 SDRAM MDCNFG Register (MDCNFG................................................................6-8
6.5.2 SDRAM Mode Register Set Configuration Register (MDMRS) ..........................6-12
6.5.3 SDRAM MDREFR Register (MDREFR) .............................................................6-14
6.5.4 Fixed-Delay or Return-Clock Data Latching .......................................................6-17
6.5.5 SDRAM Memory Options ...................................................................................6-18
6.5.6 SDRAM Command Overview .............................................................................6-27
6.5.7 SDRAM Waveforms............................................................................................6-28
6.6 Synchronous Static Memory Interface.............................................................................6-32
6.6.1 Synchronous Static Memory Configuration Register (SXCNFG)........................6-32
6.6.2 Synchronous Static Memory Mode Register Set Configuration
Register (SXMRS) ..............................................................................................6-37
6.6.3 Synchronous Static Memory Timing Diagrams...................................................6-38
6.6.4 Non-SDRAM Timing SXMEM Operation ............................................................6-39
6.7 Asynchronous Static Memory ..........................................................................................6-42
6.7.1 Static Memory Interface......................................................................................6-42
6.7.2 Static Memory SA-1111 Compatibility Configuration Register (SA1111CR) ......6-44
6.7.3 Asynchronous Static Memory Control Registers (MSCx) ...................................6-46
6.7.4 ROM Interface ....................................................................................................6-50
6.7.5 SRAM Interface Overview ..................................................................................6-53
6.7.6 Variable Latency I/O (VLIO) Interface Overview.................................................6-55
6.7.7 FLASH Memory Interface ...................................................................................6-58
6.8 16-Bit PC Card/Compact Flash Interface ........................................................................6-60
6.8.1 Expansion Memory Timing Configuration Register ............................................6-60
6.8.2 Expansion Memory Configuration Register (MECR) ..........................................6-63
6.8.3 16-Bit PC Card Overview....................................................................................6-64
6.8.4 External Logic for 16-Bit PC Card Implementation .............................................6-66
6.8.5 Expansion Card Interface Timing Diagrams and Parameters ............................6-69
6.9 Companion Chip Interface ...............................................................................................6-70
6.9.1 Alternate Bus Master Mode ................................................................................6-72
6.10 Options and Settings for Boot Memory............................................................................6-74
6.10.1 Alternate Booting ................................................................................................6-74
6.10.2 Boot Time Defaults .............................................................................................6-74
6.10.3 Memory Interface Reset and Initialization...........................................................6-78
6.11 Hardware, Watchdog, or Sleep Reset Operation ............................................................6-79
6.12 GPIO Reset Procedure....................................................................................................6-81
6.13 Memory Controller Register Summary ............................................................................6-81
7 LCD Controller..............................................................................................................................7-1
7.1 Overview............................................................................................................................7-1
7.1.1 Features................................................................................................................7-2
7.1.2 Pin Descriptions....................................................................................................7-4
7.2 LCD Controller Operation ..................................................................................................7-4
vi Intel® PXA255 Processor Developer's Manual