
172
2543L–AVR–08/10
ATtiny2313
Notes: 1.
tWLRH is valid for the Write Flash, Write EEPROM, Write Fuse bits and Write Lock bits
commands.
2. tWLRH_CE is valid for the Chip Erase command.
Serial
Downloading
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
mapping for SPI programming is listed. Not all parts use the SPI pins dedicated for the internal
SPI interface.
Figure 78. Serial Programming and Verify
(1) Notes: 1. If the device is clocked by the internal Oscillator, it is no need to connect a clock source to the
XTAL1 pin.
2. VCC - 0.3V < AVCC < VCC + 0.3V, however, AVCC should always be within 1.8 - 5.5V
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 fck < 12 MHz, 3 CPU clock cycles for fck >= 12 MHz
High:> 2 CPU clock cycles for fck < 12 MHz, 3 CPU clock cycles for fck >= 12 MHz
tBVDV
BS1 Valid to DATA valid
0
250
ns
tOLDV
OE Low to DATA Valid
250
ns
tOHDZ
OE High to DATA Tri-stated
250
ns
Table 76. Parallel Programming Characteristics, VCC = 5V ± 10% (Continued)
Symbol
Parameter
Min
Typ
Max
Units
VCC
GND
XTAL1
SCK
MISO
MOSI
RESET
+1.8 - 5.5V