Description
M58LT256JST, M58LT256JSB
1
Description
The M58LT256JST/B are 256 Mbit (16 Mbit x 16) non-volatile secure Flash memories. They
may be erased electrically at block level and programmed in-system on a word-by-word
basis using a 1.7 V to 2.0 V V
DD
supply for the circuitry and a 2.7 V to 3.6 V V
DDQ
supply for
the input/output pins. An optional 9 V V
PP
power supply is provided to speed up factory
programming.
The devices feature an asymmetrical block architecture. The M58LT256JST/B have an array
of 259 blocks, and are divided into 16 Mbit banks. There are 15 banks each containing 16
main blocks of 64 Kwords, and one parameter bank containing 4 parameter blocks of 16
KWords and 15 main blocks of 64 KWords.
The multiple bank architecture allows dual operations. While programming or erasing in one
bank, read operations are possible in other banks. Only one bank at a time is allowed to be
in program or erase mode. It is possible to perform burst reads that cross bank boundaries.
The bank architecture is summarized in
and the memory map is shown in
The parameter blocks are located at the top of the memory address space for the
M58LT256JST, and at the bottom for the M58LT256JSB.
Each block can be erased separately. Erase can be suspended to perform a program or
read operation in any other block, and then resumed. Program can be suspended to read
data at any memory location except for the one being programmed, and then resumed.
Each block can be programmed and erased over 100 000 cycles using the supply voltage
V
DD
. There is a buffer enhanced factory programming command available to speed up
programming.
Program and erase commands are written to the command interface of the memory. An
internal Program/Erase Controller manages the timings necessary for program and erase
operations. The end of a program or erase operation can be detected and any error
conditions identified in the Status Register. The command set required to control the
memory is consistent with JEDEC standards.
The device supports synchronous burst read and asynchronous read from all blocks of the
memory array. At power-up the device is configured for asynchronous read. In synchronous
burst read mode, data is output on each clock cycle at frequencies of up to 52 MHz. The
synchronous burst read operation can be suspended and resumed.
The device features an automatic standby mode. When the bus is inactive during
asynchronous read operations, the device automatically switches to the automatic standby
mode. In this condition the power consumption is reduced to the standby value and the
outputs are still driven.
The M58LT256JST/B features an instant, individual block protection scheme that allows any
block to be protected or unprotected with no latency, enabling instant code and data
protection. They can be protected individually preventing any accidental programming or
erasure. There is an additional hardware protection against program and erase. When
V
PP
≤V
PPLK
all blocks are protected against program or erase. All blocks are protected at
power-up.
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NUMONYX [ NUMONYX B.V ]
