ATTINY25V-15ST Atmel, ATTINY25V-15ST Datasheet - Page 138

• Manufacturer Part Number: ATTINY25V-15ST
• Description: MCU AVR 2K FLASH 4MHZ 8-SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY25V-15ST

• Package / Case: 8-SOIC (3.9mm Width)
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Speed: 8MHz
• Number Of I /o: 6
• Eeprom Size: 128 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Program Memory Size: 2KB (2K x 8)
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: USI
• Core Size: 8-Bit
• Processor Series: ATTINY2x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 128 B
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

21.6
21.6.1
138
Serial Downloading
ATtiny25/45/85
Serial Programming Algorithm
Both the Flash and EEPROM memory arrays can be programmed using the serial SPI bus while
RESET is pulled to GND. The serial interface consists of pins SCK, MOSI (input) and MISO (out-
put). After RESET is set low, the Programming Enable instruction needs to be executed first
before program/erase operations can be executed. NOTE, in
mapping for SPI programming is listed. Not all parts use the SPI pins dedicated for the internal
SPI interface.
Figure 21-1. Serial Programming and Verify
Notes:
Table 21-8.
When programming the EEPROM, an auto-erase cycle is built into the self-timed programming
operation (in the Serial mode ONLY) and there is no need to first execute the Chip Erase
instruction. The Chip Erase operation turns the content of every memory location in both the
Program and EEPROM arrays into 0xFF.
Depending on CKSEL Fuses, a valid clock must be present. The minimum low and high periods
for the serial clock (SCK) input are defined as follows:
Low: > 2 CPU clock cycles for f
High: > 2 CPU clock cycles for f
When writing serial data to the ATtiny25/45/85, data is clocked on the rising edge of SCK.
When reading data from the ATtiny25/45/85, data is clocked on the falling edge of SCK. See
Figure 21-2
1. If the device is clocked by the internal Oscillator, it is no need to connect a clock source to the
Symbol
MOSI
MISO
SCK
CLKI pin.
and
Pin Mapping Serial Programming
Figure 21-3
MOSI
MISO
for timing details.
SCK
Pins
PB0
PB1
PB2
ck
ck
< 12 MHz, 3 CPU clock cycles for f
< 12 MHz, 3 CPU clock cycles for f
RESET
GND
(1)
I/O
O
I
I
VCC
+4.5 - 5.5V
Table 21-8 on page
Serial Data out
ck
ck
Serial Data in
Description
Serial Clock
>= 12 MHz
>= 12 MHz
7598H–AVR–07/09
138, the pin