ATTINY461-20SUR Atmel, ATTINY461-20SUR Datasheet - Page 179

• 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

18.7.2
2588E–AVR–08/10
Entering Programming Mode
Table 18-13. Pin Values Used to Enter Programming Mode
The XA1/XA0 pins determine the action executed when the XTAL1 pin is given a positive pulse.
The bit coding is shown in
Table 18-14. XA1 and XA0 Coding
When pulsing WR or OE, the command loaded determines the action executed. The different
Commands are shown in
Table 18-15. Command Byte Bit Coding
The following algorithm puts the device in parallel programming mode:
Command Byte
1. Apply 4.5 - 5.5V between V
2. Set RESET to “0” and toggle XTAL1 at least six times.
3. Set Prog_enable pins listed in
4. Apply 11.5 - 12.5V to RESET. Any activity on Prog_enable pins within 100 ns after
5. Wait at least 50 µs before sending a new command.
XA1
0
0
1
1
ns.
+12V has been applied to RESET, will cause the device to fail entering programming
mode.
1000 0000
0100 0000
0010 0000
0001 0000
0001 0001
0000 1000
0000 0100
0000 0010
0000 0011
PAGEL/BS1
XA1/BS2
XA0
XA0
WR
Pin
0
1
0
1
Action when XTAL1 is Pulsed
Load Flash or EEPROM Address (High or low address byte determined by BS1).
Load Data (High or Low data byte for Flash determined by BS1).
Load Command
No Action, Idle
Table
Table
Command Executed
Chip Erase
Write Fuse bits
Write Lock bits
Write Flash
Write EEPROM
Read Signature Bytes and Calibration byte
Read Fuse and Lock bits
Read Flash
Read EEPROM
18-15.
18-14.
CC
and GND.
Table 18-13 on page 179
Prog_enable[3]
Prog_enable[2]
Prog_enable[1]
Prog_enable[0]
Symbol
to “0000” and wait at least 100
Value
0
0
0
0
179