ATtiny461A Atmel Corporation, ATtiny461A Datasheet - Page 168

• Manufacturer Part Number: ATtiny461A
• Manufacturer: Atmel Corporation

Specifications of ATtiny461A

• Flash (kbytes): 4 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 16
• Ext Interrupts: 16
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 256
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

18. Memory Programming
18.1
168
Program And Data Memory Lock Bits
ATtiny261A/461A/861A
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
Lock Bit Byte
LB Mode
LB2
LB1
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
165.
1
1
0
Bit No
(1) (2)
7
6
5
4
3
2
1
0
LB1
1
0
0
Description
–
–
–
–
–
–
Lock bit
Lock bit
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
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)
8197C–AVR–05/11
(1)