ATtiny24A Atmel Corporation, ATtiny24A Datasheet - Page 158

• Manufacturer Part Number: ATtiny24A
• Manufacturer: Atmel Corporation

Specifications of ATtiny24A

• Flash (kbytes): 2 Kbytes
• Pin Count: 14
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 4
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 12
• Ext Interrupts: 12
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.12
• Eeprom (bytes): 128
• 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: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

19. Memory Programming
19.1
158
Program And Data Memory Lock Bits
ATtiny24A/44A/84A
This section describes the different methods for programming ATtiny24A/44A/84A memories.
The ATtiny24A/44A/84A provides two lock bits which can be left unprogrammed (“1”) or can be
programmed (“0”) to obtain the additional security listed in
erased to “1” with the Chip Erase command.
The device has no separate boot loader section. The SPM instruction is enabled for the whole
Flash, if the SELFPRGEN 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 19-1.
Note:
Table 19-2.
Notes:
Lock bits can also be read by device firmware. See section
Data from Software” on page
LB2
LB1
LB Mode
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
Lock Bit Byte
Lock Bit Protection Modes.
LB2
1
1
0
(1) (2)
LB1
154.
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.
debugWire is disabled.
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.
Description
–
–
–
–
–
–
Lock bit
Lock bit
(1)
debugWire is disabled.
Table
“Reading Lock, Fuse and Signature
19-2. The lock bits can only be
Default Value
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
8183D–AVR–04/11
(1)