Numonyx™ Wireless Flash Memory (W18)
and verifications necessary to manage flash memory program and erase. An internal
Status Register provides ready/busy indication results of the operation (success, fail,
and so on).
Three power-saving features– Automatic Power Savings (APS), standby, and RST# –
can significantly reduce power consumption. The device automatically enters APS mode
following read cycle completion. Standby mode begins when the system deselects the
flash memory by
de-asserting CE#. Driving RST# low produces power savings similar to standby mode.
It also resets the part to read-array mode (important for system-level reset), clears
internal Status Registers, and provides an additional level of flash write protection.
2.1
Memory Map and Partitioning
The W18 device is divided into 4-Mbit physical partitions, which allows simultaneous
RWW or RWE operations and allows users to segment code and data areas on 4-Mbit
boundaries. The device’s memory array is asymmetrically blocked, which enables
system code and data integration within a single flash device. Each block can be erased
independently in block erase mode. Simultaneous program and erase operations are
not allowed; only one partition at a time can be actively programming or erasing. See
Table 3, “Bottom Parameter Memory Map” on page 11 and Table 4, “Top Parameter
Memory Map” on page 12.
The 32-Mbit device has eight partitions, the 64-Mbit device has 16 partitions, and the
128-Mbit device has 32 partitions. Each device density contains one parameter
partition and several main partitions. The 4-Mbit parameter partition contains eight 4-
Kword parameter blocks and seven 32-Kword main blocks. Each 4-Mbit main partition
contains eight 32-Kword blocks each.
The bulk of the array is divided into main blocks that can store code or data, and
parameter blocks that allow storage of frequently updated small parameters that are
normally stored in EEPROM. By using software techniques, the word-rewrite
functionality of EEPROMs can be emulated.
.
Datasheet
10
November 2007
Order Number: 290701-18
NUMONYX [ NUMONYX B.V ]
