D[15:0]
WAIT
Data
OEOFFTIME
RDCYCLETIME
OEONTIME = 0
CSRDOFFTIME = RDCYCLETIME
CSONTIME = 0
RDACCESSTIME
nBE0/CLE
nCS
nOE/nRE
nADV/ALE
GPMC
7.1.3.3.12.1.5 NAND Device Data Read and Write Phase Control in Stream Mode
NAND device data read and write accesses are achieved through a read or write request to the chip-
select-associated memory region at any address location in the region or through a read or write request
to the GPMC_NAND_DATA_i location mapped in the chip-select-associated control register region.
GPMC_NAND_DATA_i is not a true register, but an address location to enable REn or WEn signal
control. The associated chip-select signal timing control must be programmed according to the NAND
device timing specification.
Reading data from the GPMC_NAND_DATA_i location or from any location in the associated chip-select
memory region activates an asynchronous read access.
•
CSn is controlled by the CSONTIME and CSRDOFFTIME timing parameters.
•
REn is controlled by the OEONTIME and OEOFFTIME timing parameters.
•
To take advantage of REn high-to-data invalid minimum timing value, the RDACCESSTIME can be set
so that data are effectively captured after REn deassertion. This allows optimization of NAND read
access cycle time completion. For optimal timing parameter settings, see the NAND device and the
device IC timing parameters.
ALE, CLE, and WEn are maintained inactive.
shows the NAND data read cycle.
Figure 7-29. NAND Data Read Cycle
Writing data to the GPMC_NAND_DATA_i location or to any location in the associated chip-select
memory region activates an asynchronous write access.
•
CSn is controlled by the CSONTIME and CSWROFFTIME timing parameters.
•
WEn is controlled by the WEONTIME and WEOFFTIME timing parameters.
•
ALE, CLE, and REn (OEn) are maintained inactive.
shows the NAND data write cycle.
306
Memory Subsystem
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated