NAND128-A STMicroelectronics, NAND128-A Datasheet - Page 52

• Manufacturer Part Number: NAND128-A
• Description: 128 Mbit / 256 Mbit / 512 Mbit / 1 Gbit (x8/x16) 528 Byte/264 Word Page / 1.8V/3V / NAND Flash Memories
• Manufacturer: STMicroelectronics

NAND128-A, NAND256-A, NAND512-A, NAND01G-A
APPENDIX A. HARDWARE INTERFACE EXAMPLES
Nand Flash devices can be connected to a micro-
controller system bus for code and data storage.
For microcontrollers that have an embedded
NAND controller the NAND Flash can be connect-
ed without the addition of glue logic (see
Figure
required for general purpose microcontrollers that
do not have an embedded NAND controller. The
glue logic usually consists of a flip-flop to hold the
Chip Enable, Address Latch Enable and Com-
mand Latch Enable signals stable during com-
mand and address latch operations, and some
logic gates to simplify the firmware or make the de-
sign more robust.
Figure 44.
NAND Flash to a general purpose microcontroller.
The additional OR gates allow the microcontrol-
ler’s Output Enable and Write Enable signals to be
used for other peripherals. The OR gate between
Figure 43. Connection to Microcontroller, Without Glue Logic
52/55
43.). However a minimum of glue logic is
gives an example of how to connect a
Microcontroller
AD(24:16)
PWAITEN
CSn
DQ
G
W
V DD or V SS
or General Purpose I/O
A3 and CSn maps the flip-flop and NAND I/O in
different address spaces inside the same chip se-
lect unit, which improves the setup and hold times
and simplifies the firmware. The structure uses the
microcontroller DMA (Direct Memory Access) en-
gines to optimize the transfer between the NAND
Flash and the system RAM.
For any interface with glue logic, the extra delay
caused by the gates and flip-flop must be taken
into account. This delay must be added to the mi-
crocontroller’s AC characteristics and register set-
tings to get the NAND Flash setup and hold times.
For mass storage applications (hard disk emula-
tions or systems where a huge amount of storage
is required) NAND Flash memories can be con-
nected together to build storage modules (see
ure
AD17
AD16
45.).
V DD
AL
CL
R
W
E
I/O
RB
WP
NAND
Flash
AI08045b
Fig-