Datasheet

1. Enter JTAG instruction PROG_COMMANDS.
2. Enable EEPROM write using programming instruction 4a.
3. Load address high byte using programming instruction 4b.
4. Load address low byte using programming instruction 4c.
5. Load data using programming instructions 4d and 4e.
6. Repeat steps 4 and 5 for all data bytes in the page.
7. Write the data using programming instruction 4f.
8. Poll for EEPROM write complete using programming instruction 4g, or wait for t
WLRH
(refer to table
Parallel Programming Characteristics, VCC = 5V ±10% in chapter Parallel Programming
Characteristics).
9. Repeat steps 3 to 8 until all data have been programmed.
Note that the PROG_PAGELOAD instruction can not be used when programming the EEPROM
28.10.20. Reading the EEPROM
1. Enter JTAG instruction PROG_COMMANDS.
2. Enable EEPROM read using programming instruction 5a.
3. Load address using programming instructions 5b and 5c.
4. Read data using programming instruction 5d.
5. Repeat steps 3 and 4 until all data have been read.
Note that the PROG_PAGEREAD instruction can not be used when reading the EEPROM
28.10.21. Programming the Fuses
1. Enter JTAG instruction PROG_COMMANDS.
2. Enable Fuse write using programming instruction 6a.
3. Load data byte using programming instructions 6b. A bit value of “0” will program the corresponding
fuse, a “1” will unprogram the fuse.
4. Write Extended Fuse byte using programming instruction 6c.
5. Poll for Fuse write complete using programming instruction 6d, or wait for t
WLRH
(refer to table
Parallel Programming Characteristics, VCC = 5V ±10% in chapter Parallel Programming
Characteristics).
6. Load data byte using programming instructions 6e. A bit value of “0” will program the corresponding
fuse, a “1” will unprogram the fuse.
7. Write Fuse high byte using programming instruction 6f.
8. Poll for Fuse write complete using programming instruction 6g, or wait for t
WLRH
(refer to table
Parallel Programming Characteristics, VCC = 5V ±10% in chapter Parallel Programming
Characteristics).
9. Load data byte using programming instructions 6h. A “0” will program the fuse, a “1” will unprogram
the fuse.
10. Write Fuse low byte using programming instruction 6i.
11. Poll for Fuse write complete using programming instruction 6j, or wait for t
WLRH
(refer to table
Parallel Programming Characteristics, VCC = 5V ±10% in chapter Parallel Programming
Characteristics).
28.10.22. Programming the Lock Bits
1. Enter JTAG instruction PROG_COMMANDS.
2. Enable Lock bit write using programming instruction 7a.
Atmel ATmega644A [DATASHEET]
Atmel-42716C-ATmega644A_Datasheet_Complete-10/2016
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