Public Version
General-Purpose Memory Controller
www.ti.com
•
GPMC.
register settings:
–
WRITEMULTIPLE bit at 1 (write multiple access)
–
WRITETYPE bit at 1 (write synchronous)
–
MUXADDDATA bit at 1 (address/data-multiplexed device)
When WRACCESSTIME completes, control-signal timings are frozen during the multiple data
transactions, corresponding to the PAGEBURSTACCESSTIME multiplied by the number of remaining
data transactions.
•
Chip-select signal nCS:
–
nCS assertion time is controlled by the GPMC.
[3:0] CSONTIME field and
ensures address setup time to nCS assertion.
–
nCS deassertion time controlled by the GPMC.
[20:16] CSWROFFTIME field
and ensures address hold time to nCS deassertion.
•
Address valid signal nADV:
–
nADV assertion time is controlled by the GPMC.
[3:0] ADVONTIME field.
–
nADV deassertion time is controlled by the GPMC.
[20:16] ADVWROFFTIME
field.
•
Write enable signal nWE:
–
nWE assertion indicates a write cycle.
–
nWE assertion time is controlled by the GPMC.
[19:16] WEONTIME field.
–
nWE deassertion time is controlled by the GPMC.
[28:24] WEOFFTIME field.
NOTE:
The nWE falling edge must not be used to control the time when the burst first data is
driven in the address / data bus because some new devices require the nWE signal at
low during the address phase.
•
First write data is driven by the GPMC at WRDATAONADMUXBUS (
[19:16]), when
in address/data mux configuration. The next write data of the burst is driven on the bus at
WRACCE 1 during PAGEBURSTACCESSTIME GPMC_FCLK cycles. The last data of the
synchronous burst write is driven until WRCYCLETIME completes.
–
WRACCESSTIME is defined in the GPMC.
register.
–
The PAGEBURSTACCESSTIME parameter must be set accordingly with GPMCFCLKDIVIDER and
the memory-device internal configuration.
•
Total access time (WRCYCLETIME) corresponds to WRACCESSTIME plus the address hold time
from nCS deassertion, plus time from WRACCESSTIME to CSWROFFTIME.
–
WRCYCLETIME is defined in the GPMC.
register.
–
In
, the WRCYCLETIME programmed value equals WRCYCL
WRCYCLETIME1.
•
Direction signal DIR:
DIR is OUT during the entire access.
After a write operation, if no other access (read or write) is pending, the data bus keeps the previous
value. See
, Bus Keeping Support.
shows the same synchronous burst write access when the chip-select is configured in
address/data-multiplexed mode.
2154
Memory Subsystem
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated
Содержание OMAP36 Series
Страница 174: ...174 List of Tables SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 692: ...692 MPU Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 1084: ...1084 IVA2 2 Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 1990: ...1990 2D 3D Graphics Accelerator SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2334: ...2334 Memory Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2700: ...2700 Memory Management Units SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2868: ...2868 HDQ 1 Wire SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2974: ...2974 UART IrDA CIR SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3054: ...3054 Multichannel SPI SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3462: ...3462 MMC SD SDIO Card Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3508: ...3508 General Purpose Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3584: ...3584 Initialization SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3648: ...3648 Debug and Emulation SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...