Public Version
General-Purpose Memory Controller
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•
One DMA request goes from GPMC (GPMC_DMA_REQ) to the system DMA (sDMA) : S_DMA_3.
10.1.3.3 GPMC Address and Data Bus
The current application supports GPMC connection to address/data-multiplexed memory and a NAND
device. Connection to a nonmultiplexed address/data memory is supported with an address range of only
2 Kbytes.
Depending on the GPMC configuration on each chip-select, address and data-bus lines that are not
required for a particular access protocol are not updated (changed from current value) and are not
sampled when input (input data bus).
The current application supports GPMC connection to address/data-multiplexed memory,
address/data-nonmultiplexed memory with limited address (2 Kbytes), and a NAND device:
•
When the GPMC.
[1] LIMITEDADDRESS bit is set to 1, only gpmc_a[11:1] address
lines are used. This limits the memory support to 2K-byte addressable memories.
•
For address/data-multiplexed NOR devices, the address is multiplexed on the data bus.
•
8-bit wide NOR devices do not use GPMC I/O: gpmc_d[15:8] for data (they are used for address if
needed).
•
16-bit wide NAND devices do not use GPMC I/O: gpmc_a[11:1] .
•
8-bit wide NAND devices do not use GPMC I/O: gpmc_a[11:1] and GPMC I/O: gpmc_d[15:8].
CAUTION
Before trying to access a chip-select configured with a nonmultiplexed protocol,
set the LIMITEDADDRESS bit control.
10.1.3.3.1 GPMC I/O Configuration Setting (in Default Pinout Mode 0)
NOTE:
In this section, the i in
stands for the GPMC chip-select i where i = 0 to
7.
The address/data-nonmultiplexed device, which is limited to a 2K-byte address range, is selected by
programming the following register fields:
•
GPMC.
[11:10] DEVICETYPE field = 0x00
•
GPMC.
[9] MUXADDDATA bit = 0
•
GPMC.
[1] LIMITEDADDRESS bit = 1
NOTE:
The LIMITEDADDRESS field applies only to address/data-nonmultiplexed devices; it has no
effect on other device types (address/data-multiplexed, NAND).
To select the address/data-multiplexed device, program the following register fields:
•
GPMC.
[11:10] DEVICETYPE field = 0b00
•
GPMC.
[9] MUXADDDATA bit = 1
To select the NAND device, program the following register field:
•
GPMC.
[11:10] DEVICETYPE field = 0b10
•
GPMC.
[9] MUXADDDATA bit = 0
10.1.3.3.2 GPMC CS0 Default Configuration at IC Reset
To ensure a correct external boot with a GPMC access from IC reset time on CS0, several external pins
are sampled:
•
The sys_boot[4:0] pins (device boundary) define the sequence of interfaces and devices to use for
booting.
2120
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 ...