ATTINY861A-SU Atmel, ATTINY861A-SU Datasheet - Page 167

• Manufacturer Part Number: ATTINY861A-SU
• Description: IC, MCU, 8BIT, 8K FLASH, 20SOIC
• Manufacturer: Atmel

Specifications of ATTINY861A-SU

• Controller Family/series: ATtiny
• No. Of I/o's: 16
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 512Byte
• Cpu Speed: 20MHz
• No.: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 8KB
• Oscillator Type: External, Internal
• Rohs Compliant: Yes

18. Memory Programming
18.1
8197B–AVR–01/10
Program And Data Memory Lock Bits
This section describes the different methods for programming ATtiny261A/461A/861A
memories.
The device provides two lock bits which can be left unprogrammed (“1”) or can be programmed
(“0”) to obtain the additional security listed in
with the Chip Erase command.
The device 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.
Program memory can be read out via the debugWIRE interface when the DWEN fuse is pro-
grammed, even if lock bits are set. Thus, when lock bit security is required, debugWIRE should
always be disabled by clearing the DWEN fuse.
Table 18-1.
Note:
Table 18-2.
Notes:
Lock bits can also be read by device firmware. See section
Software” on page
LB2
LB1
LB Mode
Lock Bit Byte
Memory Lock Bits
1
2
3
“1” means unprogrammed, “0” means programmed.
1. Program fuse bits before programming LB1 and LB2.
2. “1” means unprogrammed, “0” means programmed.
Lock Bit Byte
Lock Bit Protection Modes.
LB2
164.
1
1
0
(1) (2)
LB1
1
0
0
Bit No
7
6
5
4
3
2
1
0
Protection Type
No memory lock features enabled.
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.
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.
Table
Description
–
–
–
–
–
–
Lock bit
Lock bit
18-2. The lock bits can only be erased to “1”
(1)
“Reading Fuse and Lock Bits from
Default Value
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
(1)
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