ade7166 Analog Devices, Inc., ade7166 Datasheet - Page 103

• Manufacturer Part Number: ade7166
• Description: Single-phase Energy Measurement Ic With 8052 Mcu, Rtc, And Lcd Driver
• Manufacturer: Analog Devices, Inc.

FLASH MEMORY
OVERVIEW
Flash memory is a type of nonvolatile memory that is in-circuit
programmable. The default state of a byte of flash memory is 0xFF
(erased). When a byte of flash memory is programmed, the
required bits change from 1 to 0. The flash memory must be
erased to turn the 0s back to 1s. However, a byte of flash
memory cannot be erased individually. The entire segment, or
page, of flash memory that contains the byte must be erased.
The ADE7566/ADE7569/ADE7166/ADE7169 provide 16 kB of
flash program/ information memory. This memory is segmented
into 32 pages of 512 bytes each. Therefore, to reprogram one
byte of flash memory, the other 511 bytes in that page must be
erased. The flash memory can be erased by page or all at once
in a mass erase. There is a command to verify that a flash write
operation has completed successfully. The ADE7566/ADE7569/
ADE7166/ADE7169 flash memory controller also offers
configurable flash memory protection.
The 16 kB of flash memory are provided on-chip to facilitate
code execution without any external discrete ROM device
requirements. The program memory can be programmed in-
circuit, using the serial download or emulation options provided or
using conventional third party memory programmers.
Flash/EE Memory Reliability
The flash memory arrays on the ADE7566/ADE7569/
ADE7166/ADE7169 are fully qualified for two key Flash/EE
memory characteristics: Flash/EE memory cycling endurance
and Flash/EE memory data retention.
Endurance quantifies the ability of the Flash/EE memory to be
cycled through many program, read, and erase cycles. In real
terms, a single endurance cycle is composed of the following four
independent, sequential events:
1.
2.
3.
4.
Initial page erase sequence.
Read/verify sequence.
Byte program sequence.
Second read/verify sequence.
Rev. A | Page 103 of 144
In reliability qualification, every byte in both the program and
data Flash/EE memory is cycled from 0x00 to 0xFF until a first
fail is recorded, signifying the endurance limit of the on-chip
Flash/EE memory.
As indicated in the Specifications section, the
ADE7566/ADE7569/ADE7166/ADE7169 flash memory
endurance qualification has been carried out in accordance with
JEDEC Standard 22 Method A117 over the industrial temperature
range of −40°C, +25°C, and +85°C. The results allow the
specification of a minimum endurance figure over supply and
temperature of 100,000 cycles, with a minimum endurance figure
of 20,000 cycles of operation at 25°C.
Retention is the ability of the flash memory to retain its
programmed data over time. Again, the parts have been qualified
in accordance with the formal JEDEC Standard 22 Method
A117 at a specific junction temperature (T
qualification procedure, the flash memory is cycled to its
specified endurance limit before data retention is characterized.
This means that the flash memory is guaranteed to retain its data
for its full specified retention lifetime every time the flash
memory is reprogrammed. It should also be noted that
retention lifetime, based on an activation energy of 0.6 eV,
derates with T
ADE7566/ADE7569/ADE7166/ADE7169
300
250
200
150
100
50
0
40
J
Figure 91. Flash/EE Memory Data Retention
as shown in
50
T
J
60
JUNCTION TEMPERATURE (°C)
ANALOG DEVICES
Figure 91.
SPECIFICATION
100 YEARS MIN.
AT T
70
J
= 55 ° C
80
J
= 55°C). As part of this
90
100
110