ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 167

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

21.6
7701E–AVR–02/11
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 (output). After RESET is set low, the Programming Enable instruction needs to be exe-
cuted first before program/erase operations can be executed. NOTE, in
167, the pin 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
Note:
Table 21-9.
When programming the EEPROM, an auto-erase cycle is built into the self-timed program-
ming operation (in 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 the 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
1. If the device is clocked by the internal oscillator, it is not needed to connect a clock source to
Symbol
MOSI
MISO
SCK
the CLKI pin.
Pin Mapping Serial Programming
Atmel ATtiny24/44/84 [Preliminary]
MOSI
MISO
SCK
ck
ck
Pins
PA6
PA5
PA4
< 12MHz, 3 CPU clock cycles for f
< 12MHz, 3 CPU clock cycles for f
RESET
GND
(1)
VCC
I/O
O
I
I
+1.8 - 5.5V
ck
ck
>= 12MHz
>= 12MHz
Description
Serial Data in
Serial Data out
Serial Clock
Table 21-9 on page
167