vi Intel® PXA255 Processor Developer’s Manual
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 Mo de 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 Asynchronous Static Memory Control Registers (MSCx)...................................6-44
6.7.3 ROM Interface....................................................................................................6-48
6.7.4 SRAM Interface Overview..................................................................................6-51
6.7.5 Variable Latency I/O (VLIO) Interface Overview.................................................6-53
6.7.6 FLASH Memory Interface...................................................................................6-56
6.8 16-Bit PC Card/Compact Flash Interface........................................................................6-58
6.8.1 Expansion Memory Timing Configuration Register............................................6-58
6.8.2 Expansion Memory Configuration Register (MECR)..........................................6-61
6.8.3 16-Bit PC Card Overview....................................................................................6-62
6.8.4 External Logic for 16-Bit PC Card Implementation.............................................6-64
6.8.5 Expansion Card Interface Timing Diagrams and Parameters............................6-67
6.9 Companion Chip Interface.............................................. ........................................... ......6-68
6.9.1 Alternate Bus Master Mode................................................................................6-70
6.10 Options and Settings for Boot Memory............................................................................6-72
6.10.1 Alternate Booting................................................................................................6-72
6.10.2 Boot Time Defaults.............................................................................................6-72
6.10.3 Memory Interface Reset and Initialization...........................................................6-76
6.11 Hardware, Watchdog, or Sleep Reset Operation............................................................6-77
6.12 GPIO Reset Procedure....................................................................................................6-79
6.13 Memory Controller Register Summary............................................................................6-79
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
7.2.1 Enabling the Controller.........................................................................................7-4