ATmega8HVA Atmel Corporation, ATmega8HVA Datasheet - Page 157

• Manufacturer Part Number: ATmega8HVA
• Manufacturer: Atmel Corporation

Specifications of ATmega8HVA

• Flash (kbytes): 8 Kbytes
• Pin Count: 28
• Max. Operating Frequency: 4 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 3
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 6
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 6
• Adc Resolution (bits): 12
• Adc Speed (ksps): 1.9
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 256
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -20 to 85
• I/o Supply Class: 1.8 to 9.0
• Operating Voltage (vcc): 1.8 to 9.0
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 2
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

27.8
27.8.1
27.8.2
8024A–AVR–04/08
High-voltage Serial Programming Algorithm
Enter High-voltage Serial Programming Mode
Considerations for Efficient Programming
To program and verify the ATmega8HVA/16HVA in the High-voltage Serial Programming mode,
the following sequence is recommended (See instruction formats in
The following algorithm puts the device in Serial (High-voltage) Programming mode:
1. Set Prog_enable pins listed in
2. Apply 3.0 - 3.5V between V
3. Wait 20 - 60 µs, and apply V
4. Keep the Prog_enable pins unchanged for at least t
5. Release Prog_enable[1] pin to avoid drive contention on the Prog_enable[1]/SDO pin.
6. Wait at least 300 µs before giving any serial instructions on SDI/SII.
If the rise time of the V
tive algorithm can be used.
1. Set Prog_enable pins listed in
2. Apply 3.0 - 3.5V between V
3. Monitor V
4. Keep the Prog_enable pins unchanged for at least t
5. Release Prog_enable[1] pin to avoid drive contention on the Prog_enable[1]/SDO pin.
6. Wait until V
Table 27-13. High-voltage Reset Characteristics
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
• Address High byte needs only be loaded before programming or reading a new 256 word
EESAVE Fuse is programmed) and Flash after a Chip Erase.
window in Flash or 256 byte EEPROM. This consideration also applies to Signature bytes
reading.
Supply Voltage
V
next 20 µs.
applied to ensure the Prog_enable Signature has been latched.
V
applied to ensure the Prog_enable Signature has been latched.
CC
CC
3.0V
3.5V
V
to 0V.
to 0V.
CC
CC
CC
, and as soon as V
actually reaches 3.0 - 3.5V before giving any serial instructions on SDI/SII.
RESET Pin High-voltage Threshold
CC
is unable to fulfill the requirements listed above, the following alterna-
CC
CC
HRST
and GND. Ensure that V
Table 27-12 on page 156
Table 27-12 on page 156
and GND.
CC
V
11.5V
11.5V
HVRST
- 12.5V to RESET.
reaches 0.9 - 1.1V, apply V
ATmega8HVA/16HVA
HVRST
HVRST
CC
to “0000”, RESET pin to 0V and
to “0000”, RESET pin to 0V and
after the High-voltage has been
after the High-voltage has been
reaches at least 1.8V within the
Minimum High-voltage Period for
HRST
Latching Prog_enable
Table
- 12.5V to RESET.
27-14):
t
10 µs
10 µs
HVRST
157