ATmega32A datasheet(266/352 Pages) ATMEL

266 / 352 page

266

8155B–AVR–07/09

ATmega32A

26. Memory Programming

26.1

Program And Data Memory Lock Bits

The ATmega32A provides six Lock bits which can be left unprogrammed (“1”) or can be pro-

grammed (“0”) to obtain the additional features listed in Table 26-2. The Lock bits can only be

erased to “1” with the Chip Erase command.

Note:

1. “1” means unprogrammed, “0” means programmed

Table 26-1.

Lock Bit Byte(1)

Lock Bit Byte

Bit No.

Description

Default Value

–

1 (unprogrammed)

–

1 (unprogrammed)

BLB12

Boot Lock bit

1 (unprogrammed)

BLB11

Boot Lock bit

1 (unprogrammed)

BLB02

Boot Lock bit

1 (unprogrammed)

BLB01

Boot Lock bit

1 (unprogrammed)

LB2

Lock bit

1 (unprogrammed)

LB1

Lock bit

1 (unprogrammed)

Table 26-2.

Lock Bit Protection Modes

Memory Lock Bits(2)

Protection Type

LB Mode

LB2

LB1

No memory lock features enabled.

Further programming of the Flash and EEPROM is disabled in

Parallel and SPI/JTAG Serial Programming mode. The Fuse bits

are locked in both Serial and Parallel Programming mode.(1)

Further programming and verification of the Flash and EEPROM

is disabled in Parallel and SPI/JTAG Serial Programming mode.

The Fuse bits are locked in both Serial and Parallel

Programming mode.(1)

BLB0 Mode

BLB02

BLB01

No restrictions for SPM or LPM accessing the Application

section.

SPM is not allowed to write to the Application section.

SPM is not allowed to write to the Application section, and LPM

executing from the Boot Loader section is not allowed to read

from the Application section. If interrupt vectors are placed in the

Boot Loader section, interrupts are disabled while executing

from the Application section.

LPM executing from the Boot Loader section is not allowed to

read from the Application section. If interrupt vectors are placed

in the Boot Loader section, interrupts are disabled while

executing from the Application section.

ATmega32A Datasheet(PDF) 266 Page - ATMEL Corporation

ATmega32A Datasheet(HTML) 266 Page - ATMEL Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL