Datasheet

313
8284D–AVR–6/11
ATmega169A/PA/329A/PA/3290A/PA/649A/P/6490A/P
28.2.1 Latching of Fuses
The fuse values are latched when the device enters programming mode and changes of the
fuse values will have no effect until the part leaves Programming mode. This does not apply to
the EESAVE Fuse which will take effect once it is programmed. The fuses are also latched on
Power-up in Normal mode.
28.3 Signature Bytes
All Atmel microcontrollers have a three-byte signature code which identifies the device. This
code can be read in both serial and parallel mode, also when the device is locked. The three
bytes reside in a separate address space.
For the ATmega169A/169PA/329A/329PA/3290A/3290PA/649A/649P/6490A/6490P the signa-
ture bytes are given in Table 28-6.
28.4 Calibration Byte
The ATmega169A/169PA/329A/329PA/3290A/3290PA/649A/649P/6490A/6490P has a byte
calibration value for the internal RC Oscillator. This byte resides in the high byte of address
0x000 in the signature address space. During reset, this byte is automatically written into the
OSCCAL Register to ensure correct frequency of the calibrated RC Oscillator.
28.5 Page Size
Table 28-6. Device and JTAG ID
Part
Signature Bytes JTAG
0x000 0x001 0x002 Part Number Manufacture ID
ATmega169A 0x1E 0x94 0x11 9405 0x1F
ATmega169PA 0x1E 0x94 0x05 9405 0x1F
ATmega329A 0x1E 0x95 0x03 950B 0x1F
ATmega329PA 0x1E 0x95 0x0B 950B 0x1F
ATmega3290A 0x1E 0x95 0x04 950C 0x1F
ATmega3290PA 0x1E 0x95 0x0C 950C 0x1F
ATmega649A 0x1E 0x96 0x03 960B 0x1F
ATmega649P 0x1E 0x96 0x0B 960B 0x1F
ATmega6490A 0x1E 0x96 0x04 960C 0x1F
ATmega6490P 0x1E 0x96 0x0C 960C 0x1F
Table 28-7. No. of Words in a Page and No. of Pages in the Flash
Flash Size Page Size PCWORD No. of Pages PCPAGE PCMSB
16K words
(32Kbytes)
64 words PC[5:0] 256 PC[13:6] 13