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3.2 Configuring EMIF16 in NAND Flash Mode
SPRUGZ3A—May 2011
KeyStone Architecture External Memory Interface (EMIF16) User Guide
3-3
Chapter 3—Operating Modes
www.ti.com
3.2 Configuring EMIF16 in NAND Flash Mode
EMIF16's memory-mapped registers must be programmed to configure NAND mode.
In addition to configuring the fields in the Async Config Register for the chip select
under consideration, the NAND Flash Control Register (NANDFCR) also needs to be
configured.
Note—
Due to legacy considerations, CS2 will refer to chip select 0 (CE0),
CS3 will refer to chip select 1(CE1), CS4 will refer to chip select 2(CE2) and
CS5 will refer to chip select 3(CE3) in this document
.
3.3 EMIF16 Signal Description – NAND Flash
NAND Flash devices have a single multiplexed path for command, address and data
phases of the access cycle. The control signals Address Latch Enable (ALE), Command
Latch Enable (CLE), Chip Select (CS#), Write Enable (WE#) and Read Enable (RE#) are
used by the NAND to distinguish between command, address, and data-read/write
phases.
describes signals that define the NAND Flash interface.
Table 3-1
NAND interface signal description
NAND Flash Pin
Type
Description
ALE
Input
During the time ALE is HIGH, address information is transferred from
EMIFD[7:0] to on-chip address register upon a LOW-HIGH transition on
WE#. When address information is not being latched, ALE should be
driven low.
CLE
Input
During the time CLE is HIGH, information is transferred from EMIFD[7:0]
to on-chip command register on rising edge of EMIFWE. When
command information is not being latched, CLE should be driven low.
CS#
Input
Chip Select. Gates transfers between host and NAND Flash.
WE#
Input
Gates transfers from host to NAND device.
RE#
Input
Gates transfers from NAND device to host.
IO[15:0]/IO[7:0]
I/O
Bidirectional pins: Used to transfer command, data and address
information between host and NAND device.
R/B#
Output
Read/Busy pin: Used to indicate if NAND device is busy performing a
PROGRAM or ERASE operation.
End of Table 3-1