S29AS008J Datasheet, PDF (4/55 Pages) SPANSION – 8 Megabit (1M x 8-Bit / 512K x 16-Bit) CMOS 1.8 Volt-Only Boot Sector Flash Memory

Data Sheet
General Description
The S29AS008J is a 8 Mbit, 1.8 Volt-only Flash memory organized as 1,048,576 bytes or 524,288 words with
a x8/x16 bus and either top or bottom boot sector architecture. The device is offered in 48-pin TSOP and 48-
ball FBGA packages. The word-wide data (x16) appears on DQ15–DQ0; the byte-wide (x8) data appears on
DQ7–DQ0. This device is designed to be programmed and erased in-system with the standard system 1.8
volt V_CC supply. A 12.0 V V_PP or 5.0 V_CC are not required for program or erase operations. The device can
also be programmed in standard EPROM programmers.
The device offers access time of 70 ns allowing high speed microprocessors to operate without wait states. To
eliminate bus contention the device has separate chip enable (CE#), write enable (WE#) and output enable
(OE#) controls.
The device requires only a single 1.8 volt power supply for both read and write functions. Internally
generated and regulated voltages are provided for the program and erase operations.
The S29AS008J is entirely command set compatible with the JEDEC single-power-supply Flash standard.
Commands are written to the command register using standard microprocessor write timings. Register
contents serve as input to an internal state-machine that controls the erase and programming circuitry. Write
cycles also internally latch addresses and data needed for the programming and erase operations. Reading
data out of the device is similar to reading from other Flash or EPROM devices.
Device programming occurs by executing the program command sequence. This initiates the Embedded
Program algorithm—an internal algorithm that automatically times the program pulse widths and verifies
proper cell margin. The Unlock Bypass mode facilitates faster programming times by requiring only two write
cycles to program data instead of four.
Device erasure occurs by executing the erase command sequence. This initiates the Embedded Erase
algorithm—an internal algorithm that automatically preprograms the array (if it is not already programmed)
before executing the erase operation. During erase, the device automatically times the erase pulse widths
and verifies proper cell margin.
The host system can detect whether a program or erase operation is complete by observing the RY/BY# pin,
or by reading the DQ7 (Data# Polling) and DQ6 (toggle) status bits. After a program or erase cycle has been
completed, the device is ready to read array data or accept another command.
The sector erase architecture allows memory sectors to be erased and reprogrammed without affecting the
data contents of other sectors. The device is fully erased when shipped from the factory.
Hardware data protection measures include a low V_CC detector that automatically inhibits write operations
during power transitions. The hardware sector group protection feature disables both program and erase
operations in any combination of the sectors of memory. This can be achieved in-system or via programming
equipment.
The Erase Suspend/Erase Resume feature enables the user to put erase on hold for any period of time to
read data from, or program data to, any sector that is not selected for erasure. True background erase can
thus be achieved.
The hardware RESET# pin terminates any operation in progress and resets the internal state machine to
reading array data. The RESET# pin may be tied to the system reset circuitry. A system reset would thus also
reset the device, enabling the system microprocessor to read the boot-up firmware from the Flash memory.
The device offers two power-saving features. When addresses have been stable for a specified amount of
time, the device enters the automatic sleep mode. The system can also place the device into the standby
mode. Power consumption is greatly reduced in both these modes.
Spansion’s Flash technology combines years of Flash memory manufacturing experience to produce the
highest levels of quality, reliability and cost effectiveness. The device electrically erases all bits within a
sector simultaneously via Fowler-Nordheim tunneling. The data is programmed using hot electron
injection.
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S29AS008J
S29AS008J_00_09 November 9, 2011