Rainbow-electronics ATtiny861_V Manuel d'utilisateur télécharger pdf (Page 168)

168

2588B–AVR–11/06

ATtiny261/461/861

22. Memory Programming

This section describes the different methods for Programming the ATtiny261/461/861 memories.

22.1 Program And Data Memory Lock Bits

The ATtiny261/461/861 provides two Lock bits which can be left unprogrammed (“1”) or can be

programmed (“0”) to obtain the additional security listed in Table 22-2. The Lock bits can only be

erased to “1” with the Chip Erase command. The ATtiny261/461/861 has no separate Boot

Loader section. The SPM instruction is enabled for the whole Flash, if the SELFPROGEN fuse is

programmed (“0”), otherwise it is disabled.

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

Notes: 1. Program the Fuse bits before programming the LB1 and LB2.

2. “1” means unprogrammed, “0” means programmed

Table 22-1. Lock Bit Byte

(1)

Lock Bit Byte Bit No Description Default Value

7 – 1 (unprogrammed)

6 – 1 (unprogrammed)

5 – 1 (unprogrammed)

4 – 1 (unprogrammed)

3 – 1 (unprogrammed)

2 – 1 (unprogrammed)

LB2 1 Lock bit 1 (unprogrammed)

LB1 0 Lock bit 1 (unprogrammed)

Table 22-2. Lock Bit Protection Modes

(1)(2)

Memory Lock Bits Protection Type

LB Mode LB2 LB1

1 1 1 No memory lock features enabled.

210

Further programming of the Flash and EEPROM is disabled in

High-voltage and Serial Programming mode. The Fuse bits are

locked in both Serial and High-voltage Programming mode.

(1)

300

Further programming and verification of the Flash and EEPROM

is disabled in High-voltage and Serial Programming mode. The

Fuse bits are locked in both Serial and High-voltage

Programming mode.

(1)

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Rainbow-electronics ATtiny861_V Manuel d'utilisateur Page 168