ATTINY461-20SUR Atmel, ATTINY461-20SUR Datasheet - Page 180

• Manufacturer Part Number: ATTINY461-20SUR
• Description: MCU AVR 4KB FLASH 20MHZ 20SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY461-20SUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

18.7.3
18.7.4
18.7.5
180
ATtiny261/461/861
Considerations for Efficient Programming
Chip Erase
Programming the Flash
The loaded command and address are retained in the device during programming. For efficient
programming, the following should be considered:
The Chip Erase will erase the Flash and EEPROM memories plus lock bits. The Lock bits are
not reset until the program memory has been completely erased. The Fuse bits are not
changed. A Chip Erase must be performed before the Flash and/or EEPROM are
reprogrammed.
Note:
The Flash is organized in pages, see
the program data is latched into a page buffer. This allows one page of program data to be pro-
grammed simultaneously. The following procedure describes how to program the entire Flash
memory (see
• The command needs only be loaded once when writing or reading multiple memory
• Skip writing the data value 0xFF, that is the contents of the entire EEPROM (unless the
• Address high byte needs only be loaded before programming or reading a new 256 word
1. Load Command “Chip Erase”:
1. Load Command “Write Flash”:
2. Load Address Low byte:
locations.
EESAVE Fuse is programmed) and Flash after a Chip Erase.
window in Flash or 256 byte EEPROM. This consideration also applies to Signature bytes
reading.
a. Set XA1, XA0 to “10”. This enables command loading.
b. Set BS1 to “0”.
c. Set DATA to “1000 0000”. This is the command for Chip Erase.
d. Give XTAL1 a positive pulse. This loads the command.
e. Give WR a negative pulse. This starts the Chip Erase. RDY/BSY goes low.
f.
a. Set XA1, XA0 to “10”. This enables command loading.
b. Set BS1 to “0”.
c. Set DATA to “0001 0000”. This is the command for Write Flash.
d. Give XTAL1 a positive pulse. This loads the command.
a. Set XA1, XA0 to “00”. This enables address loading.
b. Keep BS1 at “0”. This selects low address.
c. Set DATA = Address low byte (0x00 - 0xFF).
d. Give XTAL1 a positive pulse. This loads the address low byte.
The EEPROM memory is preserved during Chip Erase if the EESAVE Fuse is programmed.
Wait until RDY/BSY goes high before loading a new command.
Figure 18-5
for signal waveforms):
Table 18-7 on page
173. When programming the Flash,
2588E–AVR–08/10