Rainbow Electronics ATmega162V - Manual (Page 235)

235
ATmega162/V
2513E–AVR–09/03
Parallel Programming
Enter Programming Mode The following algorithm puts the device in Parallel Programming mode:
1. Apply 4.5 - 5.5V between V
CC
and GND, and wait at least 100 µs.
2. Set RESET to “0” and toggle XTAL1 at least six times.
3. Set the Prog_enable pins listed in Table 103 on page 234 to “0000” and wait at
least 100 ns.
4. Apply 11.5 - 12.5V to RESET. Any activity on Prog_enable pins within 100 ns
after +12V has been applied to RESET, will cause the device to fail entering Pro-
gramming mode.
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.
Table 105. Command Byte Bit Coding
Command Byte Command Executed
1000 0000 Chip Erase
0100 0000 Write Fuse Bits
0010 0000 Write Lock Bits
0001 0000 Write Flash
0001 0001 Write EEPROM
0000 1000 Read Signature Bytes and Calibration byte
0000 0100 Read Fuse and Lock Bits
0000 0010 Read Flash
0000 0011 Read EEPROM
Table 106. No. of Words in a Page and no. of Pages in the Flash
Flash Size Page Size PCWORD No. of Pages PCPAGE PCMSB
8K words (16K bytes) 64 words PC[5:0] 128 PC[12:6] 12
Table 107. No. of Words in a Page and no. of Pages in the EEPROM
EEPROM Size Page Size PCWORD No. of pages PCPAGE EEAMSB
512 bytes 4 bytes EEA[1:0] 128 EEA[8:2] 8