Datasheet

258
2503Q–AVR–02/11
ATmega32(L)
Notes: 1. The default value of SUT1..0 results in maximum start-up time. SeeTable 10 on page 30 for
details.
2. The default setting of CKSEL3..0 results in internal RC Oscillator @ 1MHz. See Table 2 on
page 25 for details.
The status of the Fuse bits is not affected by Chip Erase. Note that the Fuse bits are locked if
Lock bit1 (LB1) is programmed. Program the Fuse bits before programming the Lock bits.
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.
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 ATmega32 the signature bytes are:
1. $000: $1E (indicates manufactured by Atmel)
2. $001: $95 (indicates 32 Kbytes Flash memory)
3. $002: $02 (indicates ATmega32 device when $001 is $95)
Calibration Byte The ATmega32 stores four different calibration values for the internal RC Oscillator. These bytes
resides in the signature row High Byte of the addresses 0x0000, 0x0001, 0x0002, and 0x0003
for 1, 2, 4, and 8MHz respectively. During Reset, the 1MHz value is automatically loaded into the
OSCCAL Register. If other frequencies are used, the calibration value has to be loaded manu-
ally, see “Oscillator Calibration Register – OSCCAL” on page 30 for details.
Page Size
Table 105. Fuse Low Byte
Fuse Low
Byte
Bit
No. Description Default Value
BODLEVEL 7 Brown-out Detector trigger level 1 (unprogrammed)
BODEN 6 Brown-out Detector enable 1 (unprogrammed, BOD disabled)
SUT1 5 Select start-up time 1 (unprogrammed)
(1)
SUT0 4 Select start-up time 0 (programmed)
(1)
CKSEL3 3 Select Clock source 0 (programmed)
(2)
CKSEL2 2 Select Clock source 0 (programmed)
(2)
CKSEL1 1 Select Clock source 0 (programmed)
(2)
CKSEL0 0 Select Clock source 1 (unprogrammed)
(2)
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
16K words (32 Kbytes) 64 words PC[5:0] 256 PC[13:6] 13