ATMEGA48V_11 ATMEL [ATMEL Corporation], ATMEGA48V_11 Datasheet - Page 291

• Manufacturer Part Number: ATMEGA48V_11
• Description: 8-bit Atmel Microcontroller with 4/8/16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

28.7
28.7.1
2545T–AVR–05/11
Parallel programming
Enter programming mode
Table 28-13. XA1 and XA0 coding.
Table 28-14. Command byte bit coding.
The following algorithm puts the device in Parallel (High-voltage) Programming mode:
1. Set Prog_enable pins listed in
2. Apply 4.5V - 5.5V between V
Ensure that V
3. Wait 20µs - 60µs, and apply 11.5V - 12.5V to RESET.
4. Keep the Prog_enable pins unchanged for at least 10µs after the High-voltage has been
5. Wait at least 300µs before giving any parallel programming commands.
6. Exit Programming mode by power the device down or by bringing RESET pin to 0V.
If the rise time of the V
tive algorithm can be used.
1. Set Prog_enable pins listed in
2. Apply 4.5V - 5.5V between V
3. Monitor V
XA1
Command byte
V
applied to ensure the Prog_enable Signature has been latched.
V
0
0
1
1
CC
CC
1000 0000
0100 0000
0010 0000
0001 0000
0001 0001
0000 1000
0000 0100
0000 0010
0000 0011
to 0V.
to 0V.
CC
CC
XA0
0
1
0
1
, and as soon as V
reaches at least 1.8V within the next 20µs.
Action when XTAL1 is pulsed
Load flash or EEPROM address (high or low address byte determined by BS1)
Load data (high or low data byte for flash determined by BS1)
Load command
No action, idle
Command executed
Chip erase
Write fuse bits
Write lock bits
Write flash
Write EEPROM
Read signature bytes and calibration byte
Read fuse and lock bits
Read flash
Read EEPROM
CC
is unable to fulfill the requirements listed above, the following alterna-
CC
CC
Table 28-12 on page 290
Table 28-12 on page 290
CC
and GND.
and GND.
reaches 0.9V - 1.1V, apply 11.5V - 12.5V to RESET.
to “0000”, RESET pin to 0V and
to “0000”, RESET pin to 0V and
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