Numonyx™ Embedded Flash Memory (J3 v D, Monolithic)
8.0
Bus Interface
This section provides an overview of Bus operations. Basically, there are three
operations you can do with flash memory: Read, Program (Write), and Erase.The on-
chip Write State Machine (WSM) manages all erase and program algorithms. The
system CPU provides control of all in-system read, write, and erase operations through
the system bus. All bus cycles to or from the flash memory conform to standard
microprocessor bus cycles. Table 15 summarizes the necessary states of each control
signal for different modes of operations.
Table 15: Bus Operations
STS
(Default
Mode)
OE#(2) WE#(2)
VPEN
DQ15:0
Notes
(1)
(3)
Mode
RP#
CEx
Async., Status, Query and
Identifier Reads
VIH
VIH
VIH
Enabled
Enabled
VIL
VIH
X
VIH
VIH
X
X
X
X
DOUT
High Z
High Z
High Z
High Z
High Z
4,6
Output Disable
Standby
Disable
d
Reset/Power-down
Command Writes
Array Writes(8)
VIL
VIH
VIH
X
X
X
X
X
High Z
DIN
High Z
High Z
VIL
Enabled
Enabled
VIH
VIH
VIL
VIL
6,7
8,5
VPENH
X
Notes:
1.
2.
3.
4.
5.
6.
See Table 16 for valid CEx Configurations.
OE# and WE# should never be asserted simultaneously. If done so, OE# overrides WE#.
RDeQferrefteorsDCtocDhQar[a7c:t0e}riswthicesn. WBYhTeEn#VPisENlow a≤ndVDPEQN[L1K5:0] if BYTE# is high.
, memory contents can be read but not altered.
X should be VIL or VIH for the control pins and VPENLK or VPENH for VPEN. For outputs, X should be VOL or VOH
.
In default mode, STS is VOL when the WSM is executing internal block erase, program, or a lock-bit configuration
algorithm. It is VOH (pulled up by an external pull up resistance ~= 10k) when the WSM is not busy, in block erase
suspend mode (with programming inactive), program suspend mode, or reset power-down mode.
See Table 19, “Command Bus Operations” on page 35 for valid DIN (user commands) during a Write
operation
7.
8.
Array writes are either program or erase operations. /
Table 16: Chip Enable Truth Table for 32-, 64-, 128- and 256-Mb
CE2
CE1
CE0
DEVICE
VIL
VIL
VIL
VIL
VIH
VIH
VIH
VIH
VIL
VIL
VIH
VIH
VIL
VIL
VIH
VIH
VIL
VIH
VIL
VIH
VIL
VIH
VIL
VIH
Enabled
Disabled
Disabled
Disabled
Enabled
Enabled
Enabled
Disabled
Note: For single-chip applications, CE2 and CE1 can be connected to
.
GND
The next few sections detail each of the basic flash operations and some of the
advanced features available on flash memory.
December 2007
316577-06
Datasheet
31
NUMONYX [ NUMONYX B.V ]
