Am29LV256M

The Am29LV256M is a 256 Mbit, 3.0 volt single power supply flash memory devices organized as 16,777,216 words or 33,554,432 bytes. The device has a 16-bit wide data bus that can also function as an 8-bit wide data bus by using the BYTE# input. The device can be programmed either in the host system or in standard EPROM programmers.

An access time of 100, 110, or 120 ns is available. Note that each access time has a specific operating voltage range (V ) and an I/O voltage range (V ), as CC IO specified in the Product Selector Guide and the Order- ing Information sections. The device is offered in a 56-pin TSOP or Fortified BGA package. Each device has separate chip enable (CE#), write enable (WE#) and output enable (OE#) controls.

Each Am29LV256M requires only a single 3.0 volt power supply for both read and write functions. In addition to a V  input, a high-voltage accelerated program CC (WP#/ACC) input provides shorter programming times through increased current. This feature is intended to facilitate factory throughput during system production, but may also be used in the field if desired.

Am29LV256M is entirely command set compatible with the JEDEC single-power-supply Flash standard. Commands are written to the device using standard microprocessor write timing. Write cycles also inter- nally latch addresses and data needed for the pro-gramming and erase operations.

The sector erase architecture allows memory sec- tors to be erased and reprogrammed without affecting the data contents of other sectors. Am29LV256M is fully erased when shipped from the factory.

Device programming and erasure are initiated through command sequences. Once a program or erase oper- ation has begun, the host system need only poll the DQ7 (Data# Polling) or DQ6 (toggle) status bits or monitor the Ready/Busy# (RY/BY#) output to deter- mine whether the operation is complete. To facilitate programming, an Unlock Bypass mode reduces com- mand sequence overhead by requiring only two write cycles to program data instead of four.

The VersatileI/O(TM) (V ) control allows the host sys-IO tem to set the voltage levels that the device generates and tolerates on the CE# control input and DQ I/Os to the same voltage level that is asserted on the V  pin.IO Refer to the Ordering Information section for valid VIO options.

Hardware data protection measures include a lowV _CC detector that automatically inhibits write opera- tions during power transitions. The hardware sector group protection feature disables both program and erase operations in any combination of sector groups of memory. This can be achieved in-system or via pro- gramming equipment.

The Erase Suspend/Erase Resume feature allows the host system to pause an erase operation in agiven sector to read or program any other sector and then complete the erase operation. The Program Suspend/Program Resume feature enables the host system to pause a program operation in a given sector to read any other sector and then complete the pro- gram operation.

The hardware RESET# pin terminates any operation in progress and resets the device, after which it is then ready for a new operation. The RESET# pin may be tied to the system reset circuitry. A system reset would thus also reset the device, enabling the host system to read boot-up firmware from the Flash memory device.

The device reduces power consumption in the standby mode when it detects specific voltage levels on CE# and RESET#, or when addresses have been stable for a specified period of time.

TM The SecSi  (Secured Silicon) Sector provides a 128-word/256-byte area for code or data that can be permanently protected. Once this sector is protected, no further changes within the sector can occur.

The Write Protect (WP#/ACC) feature protects the first or last sector by asserting a logic low on the WP#pin.

AMD MirrorBit flash technology combines years of Flash memory manufacturing experience to produce the highest levels of quality, reliability and cost effec- tiveness. Am29LV256M electrically erases all bits within a sector simultaneously via hot-hole assisted erase. The data is programmed using hot electron injection.