256-Mbit J3 (x8/x16)
Table 13. Chip Enable Truth Table
CE2
CE1
CE0
DEVICE
V
V
V
V
V
V
V
Enabled
Disabled
Disabled
Disabled
Enabled
Enabled
Enabled
Disabled
IL
IL
IL
V
IL
IL
IH
V
V
V
IL
IH
IH
IL
V
IL
IH
V
V
V
V
V
V
IH
IH
IH
IH
IL
IL
IL
V
V
IH
V
V
V
IH
IL
V
IH
IH
NOTE: For single-chip applications, CE2 and CE1 can be connected to V .
IL
9.1.1
9.1.2
Bus Read Operation
To perform a bus read operation, CEx (refer to Table 13 on page 33) and OE# must be asserted.
CEx is the device-select control; when active, it enables the flash memory device. OE# is the data-
output control; when active, the addressed flash memory data is driven onto the I/O bus. For all
read states, WE# and RP# must be de-asserted. See Section 7.1, “Read Operations” on page 22.
Refer to Section 10.0, “Read Operations” on page 37 for details on reading from the flash array,
and refer to Section 14.0, “Special Modes” on page 50 for details regarding all other available read
states.
Bus Write Operation
Writing commands to the Command User Interface enables various modes of operation, including
the reading of array data, CFI data, identifier codes, inspection and clearing of the Status Register,
and, when VPEN = VPENH, block erasure, program, and lock-bit configuration.
The Block Erase command requires appropriate command data and an address within the block to
be erased. The Byte/Word Program command requires the command and address of the location to
be written. Set Block Lock-Bit commands require the command and block within the device to be
locked. The Clear Block Lock-Bits command requires the command and address within the device.
The CUI does not occupy an addressable memory location. It is written when the device is enabled
and WE# is active. The address and data needed to execute a command are latched on the rising
edge of WE# or the first edge of CE0, CE1, or CE2 that disables the device (see Table 13 on
page 33). Standard microprocessor write timings are used.
9.1.3
Output Disable
With CEx asserted, and OE# at a logic-high level (VIH), the device outputs are disabled. Output
signals D[15:0] are placed in a high-impedance state.
Datasheet
33
INTEL [ INTEL ]
