attiny25v ATMEL Corporation, attiny25v Datasheet - Page 161

• Manufacturer Part Number: attiny25v
• Description: Microcontroller With 2/4/8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

20.7.4
2586K–AVR–01/08
Programming the Flash
changed. A Chip Erase must be performed before the Flash and/or EEPROM are re-
programmed.
Note:
The Flash is organized in pages, see
the program data is latched into a page buffer. This allows one page of program data to be pro-
grammed simultaneously. The following procedure describes how to program the entire Flash
memory:
When writing or reading serial data to the ATtiny25/45/85, data is clocked on the rising edge of
the serial clock, see
Figure 20-4. Addressing the Flash which is Organized in Pages
1. Load command “Chip Erase” (see
2. Wait after Instr. 3 until SDO goes high for the “Chip Erase” cycle to finish.
3. Load Command “No Operation”.
1. Load Command “Write Flash” (see
2. Load Flash Page Buffer.
3. Load Flash High Address and Program Page. Wait after Instr. 3 until SDO goes high for
4. Repeat 2 through 3 until the entire Flash is programmed or until all data has been
5. End Page Programming by Loading Command “No Operation”.
the “Page Programming” cycle to finish.
programmed.
1. The EEPROM memory is preserved during Chip Erase if the EESAVE Fuse is programmed.
PROGRAM MEMORY
PROGRAM
COUNTER
PAGE
Figure
PAGE ADDRESS
WITHIN THE FLASH
PCMSB
20-5,
PCPAGE
Figure 21-6
Table 20-12 on page
Table
Table
PAGEMSB
PCWORD
and
20-16).
20-16).
WORD ADDRESS
WITHIN A PAGE
Table 21-11
INSTRUCTION WORD
157. When programming the Flash,
PAGE
for details.
ATtiny25/45/85
PCWORD[PAGEMSB:0]:
00
01
02
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