169
8006K–AVR–10/10
ATtiny24/44/84
19.7.2
Considerations for Efficient Programming
The loaded command and address are retained in the device during programming. For efficient
programming, the following should be considered.
The command needs only be loaded once when writing or reading multiple memory
locations.
Skip writing the data value 0xFF that is the contents of the entire EEPROM (unless the
EESAVE Fuse is programmed) and Flash after a Chip Erase.
Address High byte needs only be loaded before programming or reading a new 256 word
window in Flash or 256 byte EEPROM. This consideration also applies to Signature bytes
reading.
19.7.3
Chip Erase
The Chip Erase will erase the Flash and EEPROM
(1) memories plus Lock bits. The Lock bits are
not reset until the Program memory has been completely erased. The Fuse bits are not
changed. A Chip Erase must be performed before the Flash and/or EEPROM are re-
programmed.
1.
2.
Wait after Instr. 3 until SDO goes high for the “Chip Erase” cycle to finish.
3.
Load Command “No Operation”.
Note:
1. The EEPROM memory is preserved during Chip Erase if the EESAVE Fuse is programmed.
19.7.4
Programming the Flash
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:
1.
2.
Load Flash Page Buffer.
3.
Load Flash High Address and Program Page. Wait after Instr. 3 until SDO goes high for
the “Page Programming” cycle to finish.
4.
Repeat 2 through 3 until the entire Flash is programmed or until all data has been
programmed.
5.
End Page Programming by Loading Command “No Operation”.
When writing or reading serial data to the ATtiny24/44/84, data is clocked on the rising edge of