ATMEGA1284P-AUR Atmel, ATMEGA1284P-AUR Datasheet - Page 282

• Manufacturer Part Number: ATMEGA1284P-AUR
• Description: MCU AVR 128KB FLASH 20MHZ 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA1284P-AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

25.7
8272A–AVR–01/10
Addressing the Flash During Self-Programming
The Z-pointer is used to address the SPM commands. The Z pointer consists of the Z-registers
ZL and ZH in the register file
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
addressed 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 program-
ming operation is initiated, the address is latched and the Z-pointer can be used for other
operations.
The LPM instruction use the Z-pointer to store the address. Since this instruction addresses the
Flash byte-by-byte, also bit Z0 of the Z-pointer is used.
Figure 25-3. Addressing the Flash During SPM
Note:
164A/164PA/324A/324PA/644A/644PA/1284/1284P
Bit
ZH (R31)
ZL (R30)
Z - REGISTER
1. The different variables used in
PROGRAM MEMORY
BIT
Z15
Z7
PAGE
15
PROGRAM
COUNTER
7
15
Figure
PAGE ADDRESS
WITHIN THE FLASH
ZPCMSB
PCMSB
Z14
Z6
14
25-3. Note that the Page Erase and Page Write operations are
6
PCPAGE
Z13
Z5
13
5
Figure 25-3
ZPAGEMSB
PAGEMSB
Table 26-7 on page
PCWORD
Z12
Z4
12
4
WORD ADDRESS
WITHIN A PAGE
(1)
are listed in
1
0
0
INSTRUCTION WORD
Z11
Z3
11
3
PAGE
Table 25-12 on page
298), the Program Counter can
Z10
Z2
10
2
PCWORD[PAGEMSB:0]:
00
01
02
PAGEEND
Z9
Z1
9
1
290.
Z8
Z0
8
0
282