ATMEGA8535-16JU Atmel, ATMEGA8535-16JU Datasheet - Page 233
![MCU AVR 8K ISP FLASH MEM 44-PLCC](/photos/6/70/67043/453-44-plcc_sml.jpg)
ATMEGA8535-16JU
Manufacturer Part Number
ATMEGA8535-16JU
Description
MCU AVR 8K ISP FLASH MEM 44-PLCC
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA8535-16JU
Core Processor
AVR
Core Size
8-Bit
Speed
16MHz
Connectivity
I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
32
Program Memory Size
8KB (4K x 16)
Program Memory Type
FLASH
Eeprom Size
512 x 8
Ram Size
512 x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-PLCC
Processor Series
ATMEGA8x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
512 B
Interface Type
SPI, TWI, UART
Maximum Clock Frequency
16 MHz
Number Of Programmable I/os
32
Number Of Timers
3
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
EWAVR, EWAVR-BL
Development Tools By Supplier
ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
Minimum Operating Temperature
- 40 C
On-chip Adc
10 bit, 8 Channel
Cpu Family
ATmega
Device Core
AVR
Device Core Size
8b
Frequency (max)
16MHz
Total Internal Ram Size
512Byte
# I/os (max)
32
Number Of Timers - General Purpose
3
Operating Supply Voltage (typ)
5V
Operating Supply Voltage (max)
5.5V
Operating Supply Voltage (min)
4.5V
Instruction Set Architecture
RISC
Operating Temp Range
-40C to 85C
Operating Temperature Classification
Industrial
Mounting
Surface Mount
Pin Count
44
Package Type
PLCC
For Use With
ATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEMATSTK500 - PROGRAMMER AVR STARTER KIT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
ATMEGA8535-16JU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
Preventing Flash Corruption
Programming Time for Flash
When Using SPM
Simple Assembly Code
Example for a Boot Loader
2502K–AVR–10/06
Fuse and Lock bits that are programmed, will be read as zero. Fuse and Lock bits that
are unprogrammed, will be read as one.
During periods of low V
age is too low for the CPU and the Flash to operate properly. These issues are the same
as for board level systems using the Flash, and the same design solutions should be
applied.
A Flash program corruption can be caused by two situations when the voltage is too low.
First, a regular write sequence to the Flash requires a minimum voltage to operate cor-
rectly. Secondly, the CPU itself can execute instructions incorrectly, if the supply voltage
for executing instructions is too low.
Flash corruption can easily be avoided by following these design recommendations (one
is sufficient):
1. If there is no need for a Boot Loader update in the system, program the Boot
2. Keep the AVR RESET active (low) during periods of insufficient power supply
3. Keep the AVR core in Power-down Sleep mode during periods of low V
The calibrated RC Oscillator is used to time Flash accesses. Table 92 shows the typical
programming time for Flash accesses from the CPU.
Table 92. SPM Programming Time
Symbol
Flash write (Page Erase, Page
Write, and write Lock bits by SPM)
Loader Lock bits to prevent any Boot Loader software updates.
voltage. This can be done by enabling the internal Brown-out Detector (BOD) if
the operating voltage matches the detection level. If not, an external low V
Reset Protection circuit can be used. If a Reset occurs while a write operation is
in progress, the write operation will be completed provided that the power supply
voltage is sufficient.
will prevent the CPU from attempting to decode and execute instructions, effec-
tively protecting the SPMCR Register and thus the Flash from unintentional
writes.
.equ
.org SMALLBOOTSTART
Write_page:
;-the routine writes one page of data from RAM to Flash
; the first data location in RAM is pointed to by the Y pointer
; the first data location in Flash is pointed to by the Z pointer
;-error handling is not included
;-the routine must be placed inside the boot space
; (at least the Do_spm sub routine). Only code inside NRWW section can
; be read during Self-Programming (page erase and page write).
;-registers used: r0, r1, temp1 (r16), temp2 (r17), looplo (r24),
; loophi (r25), spmcrval (r20)
; storing and restoring of registers is not included in the routine
; register usage can be optimized at the expense of code size
;-It is assumed that either the interrupt table is moved to the Boot
; loader section or that the interrupts are disabled.
; page erase
ldi
rcall
PAGESIZEB = PAGESIZE*2
spmcrval, (1<<PGERS) | (1<<SPMEN)
Do_spm
CC,
the Flash program can be corrupted because the supply volt-
Min Programming Time
;PAGESIZEB is page size in BYTES, not words
3.7 ms
ATmega8535(L)
Max Programming Time
4.5 ms
CC
. This
CC
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