ATMEGA163 ATMEL [ATMEL Corporation], ATMEGA163 Datasheet - Page 144

• Manufacturer Part Number: ATMEGA163
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Fuse Bits
Signature Bytes
Calibration Byte
144
ATmega163(L)
The ATmega163 has ten Fuse bits, divided in two groups. The Fuse High bits are
BOOTSZ1..0 and BOOTRST, and the Fuse Low bits are BODLEVEL, BODEN, SPIEN,
and CKSEL3..0.
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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.
All Atmel microcontrollers have a three-byte signature code which identifies the device.
This code can be read in both serial and parallel mode. The three bytes reside in a sep-
arate address space.
The ATmega163 the signature bytes are:
The ATmega163 has a one byte calibration value for the internal RC Oscillator. This
byte resides in the high byte of address $000 in the signature address space. During
Memory Programming, the external programmer must read this location and program it
into a selected location in the normal Flash Program memory. At start-up, the user soft-
ware must read this Flash location and write the value to the OSCCAL Register.
BOOTSZ1..0 select the size and start address of the Boot Flash section according
to Table 51 on page 134. Default value is “11” (both unprogrammed).
When BOOTRST is programmed (“0”), the Reset Vector is set to the start address of
the Boot Flash section, as selected by the BOOTSZ fuses according to Table 51 on
page 134. If the BOOTRST is unprogrammed (“1”), the Reset Vector is set to
address $0000. Default value is unprogrammed (“1”).
The BODLEVEL Fuse selects the Brown-out Detection Level and changes the Start-
up times, according to Table 4 on page 24 and Table 5 on page 25, respectively.
Default value is unprogrammed (“1”).
When the BODEN Fuse is programmed (“0”), the Brown-out Detector is enabled.
See “Reset and Interrupt Handling” on page 21. Default value is unprogrammed
(“1”).
When the SPIEN Fuse is programmed (“0”), Serial Program and Data Downloading
are enabled. Default value is programmed (“0”). The SPIEN Fuse is not accessible
in serial programming mode.
CKSEL3..0 select the clock source and the start-up delay after reset, according to
Table 1 on page 5 and Table 5 on page 25. Default value is “0010” (Internal RC
Oscillator).
1. $000: $1E (indicates manufactured by Atmel).
2. $001: $94 (indicates 16KB Flash memory).
3. $002: $02 (indicates ATmega163 device when $001 is $94).
1142E–AVR–02/03