ATmega32A Datasheet - Sunrom Technologies

ATmega32ATable 26-2.Lock Bit Protection Modes (Continued)Memory Lock Bits (2)BLB1 Mode BLB12 BLB111 1 1Notes: 1. Program the fuse bits before programming the Lock bits.2. “1” means unprogrammed, “0” means programmedNo restrictions for SPM or LPM accessing the Boot Loadersection.2 1 0 SPM is not allowed to write to the Boot Loader section.3 0 04 0 1Protection TypeSPM is not allowed to write to the Boot Loader section, and LPMexecuting from the Application section is not allowed to readfrom the Boot Loader section. If interrupt vectors are placed inthe Application section, interrupts are disabled while executingfrom the Boot Loader section.LPM executing from the Application section is not allowed toread from the Boot Loader section. If interrupt vectors areplaced in the Application section, interrupts are disabled whileexecuting from the Boot Loader section.26.2 Fuse BitsThe ATmega32A has two fuse bytes. Table 26-3 and Table 26-4 describe briefly the functionalityof all the fuses and how they are mapped into the fuse bytes. Note that the fuses are read aslogical zero, “0”, if they are programmed.Table 26-3.Fuse High ByteFuse HighByte Bit No. Description Default ValueOCDEN (4) 7 Enable OCD 1 (unprogrammed, OCD disabled)JTAGEN (5) 6 Enable JTAG 0 (programmed, JTAG enabled)SPIEN (1) 5Enable SPI Serial Program andData Downloading0 (programmed, SPI prog. enabled)CKOPT (2) 4 Oscillator options 1 (unprogrammed)EESAVE 3BOOTSZ1 2BOOTSZ0 1EEPROM memory is preservedthrough the Chip Erase1 (unprogrammed, EEPROM notpreserved)Select Boot Size (see Table 25-6for details) 0 (programmed) (3)Select Boot Size (see Table 25-6for details) 0 (programmed) (3)BOOTRST 0 Select reset vector 1 (unprogrammed)Notes: 1. The SPIEN Fuse is not accessible in SPI Serial Programming mode.2. The CKOPT Fuse functionality depends on the setting of the CKSEL bits. See See “ClockSources” on page 26. for details.3. The default value of BOOTSZ1:0 results in maximum Boot Size. See Table 25-6 on page 263.4. Never ship a product with the OCDEN Fuse programmed regardless of the setting of Lock bitsand the JTAGEN Fuse. A programmed OCDEN Fuse enables some parts of the clock systemto be running in all sleep modes. This may increase the power consumption.5. If the JTAG interface is left unconnected, the JTAGEN fuse should if possible be disabled. Thisto avoid static current at the TDO pin in the JTAG interface.8155C–AVR–02/11268