ATTINY25V-10MU Atmel, ATTINY25V-10MU Datasheet - Page 145

• Manufacturer Part Number: ATTINY25V-10MU
• Description: IC MCU AVR 2K FLASH 10MHZ 20-QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY25V-10MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 10MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 6
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-MLF®, QFN
• Processor Series: ATTINY2x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 128 B
• Interface Type: USI
• Maximum Clock Frequency: 10 MHz
• Number Of Programmable I/os: 6
• Number Of Timers: 2
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 4-ch x 10-bit
• For Use With: ATSTK600-DIP40 - STK600 SOCKET/ADAPTER 40-PDIPATAVRBC100 - REF DESIGN KIT BATTERY CHARGER770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19. Self-Programming the Flash
19.1
19.2
2586M–AVR–07/10
Performing Page Erase by SPM
Filling the Temporary Buffer (Page Loading)
The device provides a Self-Programming mechanism for downloading and uploading program
code by the MCU itself. The Self-Programming can use any available data interface and associ-
ated protocol to read code and write (program) that code into the Program memory. The SPM
instruction is disabled by default but it can be enabled by programming the SELFPRGEN fuse
(to “0”).
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 buf-
fer 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 re-written. 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 alter-
native 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.
To execute Page Erase, set up the address in the Z-pointer, write “00000011” to SPMCSR and
execute SPM within four clock cycles after writing SPMCSR. The data in R1 and R0 is ignored.
The page address must be written to PCPAGE in the Z-register. Other bits in the Z-pointer will
be ignored during this operation.
Note:
To write an instruction word, set up the address in the Z-pointer and data in R1:R0, write
“00000001” to SPMCSR and execute SPM within four clock cycles after writing SPMCSR. The
content of PCWORD in the Z-register is used to address the data in the temporary buffer. The
temporary buffer will auto-erase after a Page Write operation or by writing the CTPB bit in
SPMCSR. It is also erased after a system reset. Note that it is not possible to write more than
one time to each address without erasing the temporary buffer.
• Fill temporary page buffer
• Perform a Page Erase
• Perform a Page Write
• Perform a Page Erase
• Fill temporary page buffer
• Perform a Page Write
The CPU is halted during the Page Erase operation.
145