
515
42073A-MCU Wireless-02/13
ATmega2564/1284/644RFR2
31.8.15 Chip Erase of EEPROM only
This special Chip Erase command will erase only the EEPROM
(1) memory. The Flash,
Lock and Fuse bits are not changed. The EEPROM must be erased before it can be
reprogrammed.
Note:
1. The EEPROM memory is also preserved during this special Chip Erase if the
EESAVE Fuse is programmed.
Load Command “Chip Erase EEPROM only”
1. Set XA1, XA0 to “10”. This enables command loading.
2. Set BS1 to “0”.
3. Set DATA to “1000 0010”. This is the command for Chip Erase EEPROM only.
4. Give CLKI a positive pulse. This loads the command.
5. Give WR
___
a negative pulse. This starts the Chip Erase of the EEPROM. RDY/ BSY
___
goes low.
6. Wait until RDY/BSY
___
goes high before loading a new command.
31.8.16 Erase EEPROM Page
the EEPROM, the program data is latched into a page buffer. In contrast when erasing
the EEPROM, only the byte address is required and latched into the page buffer. The
program data are ignored. This allows erasing only selected bytes of an EEPROM
page. The algorithm for erasing EEPROM data is as follows (refer to
"Programming the1. A: Load Command “1000 0011”.
2. G: Load Address High Byte (0x00 - 0xFF).
3. B: Load Address Low Byte (0x00 - 0xFF).
4. E: Latch address (give PAGEL a positive pulse).
K: Repeat 3 through 5 until all addresses of bytes to be erased have been latched. If all
byte locations in the EEPROM page have been latched, then the entire page is erased.
L: Erase EEPROM page
1. Set BS2, BS1 to “00”.
2. Give WR
___
a negative pulse. This starts erasing of the EEPROM page. RDY/BSY
___
goes
low.
3. Wait until to RDY/BSY
___
goes high before a new program or erase operation.
Note:
1. The EEPROM memory is not preserved during the EEPROM page erase if the
EESAVE Fuse is programmed.
31.8.17 Writing User Signature Data
page 505 for details). Writing the user signature pages is similar to programming any
other page of the Flash. For programming signature pages, the user data is latched into
a page buffer. This allows one page of user signature data to be programmed at a time.
The following procedure describes how to write all user signature pages (refer to
loading):
1. A. Load Command “0001 0010” (Write User Signature Page).