ATMEGA8A-PU Atmel, ATMEGA8A-PU Datasheet - Page 217

• Manufacturer Part Number: ATMEGA8A-PU
• Description: MCU AVR 8K FLASH 16MHZ 28-PDIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8A-PU

• 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: 23
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-DIP (0.300", 7.62mm)
• Processor Series: ATMEGA8x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: SPI, TWI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 23
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 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, 6 Channel
• Package: 28PDIP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 16 MHz
• Operating Supply Voltage: 3.3|5 V
• Controller Family/series: AVR MEGA
• No. Of I/o's: 23
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 1KB
• Cpu Speed: 16MHz
• Rohs Compliant: Yes
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

23.7
8159D–AVR–02/11
Addressing the Flash During Self-Programming
Table 23-4.
Note:
The Z-pointer is used to address the SPM commands.
Since the Flash is organized in pages (see
be treated as having two different sections. One section, consisting of the least significant bits, is
addressing the words within a page, while the most significant bits are addressing the pages.
This is shown in
independently. Therefore it is of major importance that the Boot Loader software addresses the
same page in both the page erase and page write operation. Once a programming operation is
initiated, the address is latched and the Z-pointer can be used for other operations.
The only SPM operation that does not use the Z-pointer is Setting the Boot Loader Lock Bits.
The content of the Z-pointer is ignored and will have no effect on the operation. The LPM
instruction does also use the Z-pointer to store the address. Since this instruction addresses the
Flash byte by byte, also the LSB (bit Z0) of the Z-pointer is used.
Figure 23-3. Addressing the Flash during SPM
Bit
ZH (R31)
ZL (R30)
BOOTRST
Z - REGISTER
1
0
1. “1” means unprogrammed, “0” means programmed
PROGRAM MEMORY
BIT
Boot Reset Fuse
PROGRAM
COUNTER
Z15
15
PAGE
15
Z7
Figure
7
Reset Address
Reset Vector = Application Reset (address 0x0000)
Reset Vector = Boot Loader Reset (see
PAGE ADDRESS
WITHIN THE FLASH
23-3. Note that the page erase and page write operations are addressed
ZPCMSB
PCMSB
Z14
Z6
14
6
PCPAGE
(1)
Z13
Z5
13
5
ZPAGEMSB
PAGEMSB
PCWORD
Z12
Table 24-5 on page
12
Z4
4
WORD ADDRESS
WITHIN A PAGE
(1)
1
0
0
Z11
11
Z3
3
INSTRUCTION WORD
Table 23-6 on page
PAGE
Z10
10
Z2
2
229), the Program Counter can
Z9
Z1
9
1
223)
ATmega8A
PCWORD[PAGEMSB:0]:
00
01
02
PAGEEND
Z8
Z0
8
0
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