aduc7062 Analog Devices, Inc., aduc7062 Datasheet - Page 52

• Manufacturer Part Number: aduc7062
• Description: Low-power, Precision Analog Microcontroller, Dual ?-? Adcs, Flash/ee, Arm7tdmi
• Manufacturer: Analog Devices, Inc.

ADuC7060/ADuC7061/ADuC7062
NONVOLATILE FLASH/EE MEMORY
The ADuC706x incorporates Flash/EE memory technology
on-chip to provide the user with nonvolatile, in-circuit reprogram-
mable memory space.
Like EEPROM, flash memory can be programmed in-system
at a byte level, although it must first be erased. The erase is
performed in page blocks. As a result, flash memory is often,
and more correctly referred to as Flash/EE memory.
Overall, Flash/EE memory represents a step closer to the
ideal memory device that includes nonvolatility, in-circuit
programmability, high density, and low cost. Incorporated in
the ADuC706x, Flash/EE memory technology allows the user
to update program code space in-circuit, without the need to
replace one time programmable (OTP) devices at remote
operating nodes.
Each part contains a 64 kB array of Flash/EE memory. The
lower 62 kB is available to the user and the upper 2 kB contain
permanently embedded firmware, allowing in-circuit serial
download. These 2 kB of embedded firmware also contain a
power-on configuration routine that downloads factory-
calibrated coefficients to the various calibrated peripherals
(such as ADC, temperature sensor, and band gap references).
This 2 kB embedded firmware is hidden from user code.
FLASH/EE MEMORY RELIABILITY
The Flash/EE memory arrays on the parts 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. A single
endurance cycle is composed of four independent, sequential
events, defined as
•
•
•
•
In reliability qualification, every half word (16-bit wide)
location of the three pages (top, middle, and bottom) in the
Flash/EE memory is cycled 10,000 times from 0x0000 to
0xFFFF. The Flash/EE memory endurance qualification is
carried out in accordance with JEDEC Retention Lifetime
Specification A117 over the industrial temperature range of
−40° to +125°C. The results allow the specification of a
minimum endurance figure over a supply temperature of
10,000 cycles.
Initial page erase sequence.
Read/verify sequence a single Flash/EE.
Byte program sequence memory.
Second read/verify sequence endurance cycle.
Rev. PrA | Page 52 of 100
Retention quantifies the ability of the Flash/EE memory to
retain its programmed data over time. Again, the parts are
qualified in accordance with the formal JEDEC Retention
Lifetime Specification A117 at a specific junction temperature
(T
Flash/EE memory is cycled to its specified endurance limit,
described previously, before data retention is characterized.
This means that the Flash/EE memory is guaranteed to retain
its data for its fully specified retention lifetime every time the
Flash/EE memory is reprogrammed. Also note that retention
lifetime, based on activation energy of 0.6 eV, derates with T
shown in Figure 16.
PROGRAMMING
The 62 kB of Flash/EE memory can be programmed in-circuit,
using the serial download mode or the provided JTAG mode.
Serial Downloading (In-Circuit Programming)
The ADuC706x facilitates code download via the standard
UART serial port. The parts enter serial download mode after a
reset or power cycle if the BM pin is pulled low through an
external 1 kΩ resistor. Once in serial download mode, the user
can download code to the full 62 kB of Flash/EE memory while
the device is in-circuit in its target application hardware. An
executable PC serial download is provided as part of the
development system for serial downloading via the UART.
JTAG Access
The JTAG protocol uses the on-chip JTAG interface to facilitate
code download and debug.
J
= 85°C). As part of this qualification procedure, the
600
450
300
150
0
30
Figure 16. Flash/EE Memory Data Retention
40
Preliminary Technical Data
JUNCTION TEMPERATURE (°C)
55
70
85
100
125
135
150
J
as