Digi NS9215 User Manual

Page 12

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12

Hardware Reference NS9215

Low-power SDRAM partial array refresh ...........................................204

Memory map...................................................................................205

Power-on reset memory map ........................................................205
Chip select 1 memory configuration ................................................205
Example: Boot from flash, SRAM mapped after boot ............................205
Example: Boot from flash, SDRAM remapped after boot ........................206

Static memory controller....................................................................207

Write protection .......................................................................208
Extended wait transfers ..............................................................208
Memory mapped peripherals.........................................................209

Static memory initialization ................................................................209

Access sequencing and memory width .............................................209
Wait state generation .................................................................209
Programmable enable.................................................................210

Static memory read control.................................................................210

Output enable programmable delay ................................................210
ROM, SRAM, and Flash ................................................................210

Static memory read: Timing and parameters ............................................211

External memory read transfer with zero wait states ...........................211
External memory read transfer with two wait states ............................211
External memory read transfer with two output enable delay states.........212
External memory read transfers with zero wait states ..........................212
Burst of zero wait states with fixed length........................................213
Burst of two wait states with fixed length ........................................213

Asynchronous page mode read .............................................................214
Asynchronous page mode read: Timing and parameters ...............................214

External memory page mode read transfer .......................................214
External memory 32-bit burst read from 8-bit memory .........................215

Static memory write control................................................................216

Write enable programming delay ...................................................216
SRAM .....................................................................................216

Static memory Write: Timing and parameters ...........................................216

External memory write transfer with zero wait states ..........................216
External memory write transfer with two wait states ...........................217
External memory write transfer with two write enable delay states .........217
Two external memory write transfers with zero wait states ...................218
Flash memory ..........................................................................218

Bus turnaround................................................................................219
Bus turnaround: Timing and parameters..................................................219

Read followed by write with no turnaround.......................................219
Write followed by a read with no turnaround.....................................220
Read followed by a write with two turnaround cycles...........................220

Byte lane control .............................................................................221
Address connectivity .........................................................................222

Memory banks constructed from 8-bit or non-byte-partitioned memory devices

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