ATTINY28V-1AC Atmel, ATTINY28V-1AC Datasheet - Page 46

• Manufacturer Part Number: ATTINY28V-1AC
• Description: IC AVR MCU 2K 1.2MHZ 1.8V 32TQFP
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY28V-1AC

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 1.2MHz
• Peripherals: POR, WDT
• Number Of I /o: 11
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Ram Size: -
• Data Converters: -
• Connectivity: -

Memory
Programming
Program Memory Lock
Bits
Fuse Bits
Signature Bytes
Calibration Byte
46
ATtiny28L/V
The ATtiny28 MCU provides two Lock bits that can be left unprogrammed (“1”) or can be
programmed (“0”) to obtain the additional features listed in Table 20. The Lock bits can
only be erased with the Chip Erase command.
Table 20. Lock Bit Protection Modes
Note:
The ATtiny28 has five Fuse bits, INTCAP and CKSEL3..0.
•
•
The status of the Fuse bits is not affected by Chip Erase.
All Atmel microcontrollers have a 3-byte signature code that identifies the device. The
three bytes reside in a separate address space.
For the ATtiny28, they are:
The ATtiny28 has one byte calibration value for the internal RC oscillator. This byte
resides in the high byte of address $000 in the signature address space. During memory
programming, the external programmer must read this location, and program it into a
selected location in the the normal Flash program memory. At start-up, the user soft-
ware must read this Flash location and write the value to the OSCCAL register.
Mode
When the INTCAP Fuse is programmed (“0”), internal load capacitors are
connected between XTAL1/XTAL2 and GND, similar to C1 and C2 in Figure 5. See
“Crystal Oscillator” on page 7. Default value is unprogrammed (“1”).
CKSEL3..0 Fuses: See Table 1, “Device Clocking Option Select,” on page 7 and
Table 5, “ATtiny28 Clock Options and Start-up Time,” on page 16, for which
combination of CKSEL3..0 to use. Default value is “0010”, internal RC oscillator with
long start-up time.
1. $000: $1E (indicates manufactured by Atmel)
2. $001: $91 (indicates 2 KB Flash memory)
3. $002: $07 (indicates ATtiny28 device when signature byte $001 is $91)
1
2
3
Memory Lock Bits
1. Further programming of the Fuse bits is also disabled. Program the Fuse bits before
programming the Lock bits.
LB1
1
0
0
LB2
1
1
0
Protection Type
No memory lock features enabled.
Further programming of the Flash is disabled.
Same as mode 2, and verify is also disabled.
(1)
1062F–AVR–07/06