ATMEGA8535L-8AC Atmel, ATMEGA8535L-8AC Datasheet - Page 230

• Manufacturer Part Number: ATMEGA8535L-8AC
• Description: IC AVR MCU 8K LV 8MHZ COM 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8535L-8AC

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• 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): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Self-Programming the
Flash
230
ATmega8535(L)
Figure 114. Addressing the Flash during SPM
Notes:
The program memory is updated in a page by page fashion. Before programming a
page with the data stored in the temporary page buffer, the page must be erased. The
temporary page buffer is filled one word at a time using SPM and the buffer can be filled
either before the Page Erase command or between a Page Erase and a Page Write
operation:
Alternative 1, fill the buffer before a Page Erase:
•
•
•
Alternative 2, fill the buffer after Page Erase:
•
•
•
If only a part of the page needs to be changed, the rest of the page must be stored (for
example in the temporary page buffer) before the erase, and then be rewritten. When
using alternative 1, the Boot Loader provides an effective Read-Modify-Write feature
which allows the user software to first read the page, do the necessary changes, and
then write back the modified data. If alternative 2 is used, it is not possible to read the
old data while loading since the page is already erased. The temporary page buffer can
be accessed in a random sequence. It is essential that the page address used in both
the page erase and page write operation is addressing the same page. See “Simple
Assembly Code Example for a Boot Loader” on page 233 for an assembly code
example.
Z - REGISTER
Fill temporary page buffer
Perform a Page Erase
Perform a Page Write
Perform a Page Erase
Fill temporary page buffer
Perform a Page Write
PROGRAM MEMORY
BIT
1. The different variables used+ in Figure 114 are listed in Table 95 on page 236.
2. PCPAGE and PCWORD are listed in Table 104 on page 241.
PROGRAM
COUNTER
15
PAGE
PAGE ADDRESS
WITHIN THE FLASH
ZPCMSB
PCMSB
PCPAGE
ZPAGEMSB
PAGEMSB
PCWORD
WORD ADDRESS
WITHIN A PAGE
(1)
1
0
0
INSTRUCTION WORD
PAGE
PCWORD[PAGEMSB:0]:
00
01
02
PAGEEND
2502K–AVR–10/06