ATMEGA325A-MU Atmel, ATMEGA325A-MU Datasheet - Page 286

• Manufacturer Part Number: ATMEGA325A-MU
• Description: IC MCU AVR 32K FLASH 64VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA325A-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

26.2.1
26.3
26.4
26.5
26.6
286
Signature Bytes
Calibration Byte
Page Size
Parallel Programming Parameters, Pin Mapping, and Commands
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/645
Latching of Fuses
The fuse values are latched when the device enters programming mode and changes of the
fuse values will have no effect until the part leaves Programming mode. This does not apply to
the EESAVE Fuse which will take effect once it is programmed. The fuses are also latched on
Power-up in Normal mode.
All Atmel microcontrollers have a three-byte signature code which identifies the device. This
code can be read in both serial and parallel mode, also when the device is locked. The three
bytes reside in a separate address space. The signature bytes are given in
Table 26-6.
The ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/6450A/6450P has a byte
calibration value for the internal RC Oscillator. This byte resides in the high byte of address
0x000 in the signature address space. During reset, this byte is automatically written into the
OSCCAL Register to ensure correct frequency of the calibrated RC Oscillator.
Table 26-7.
Table 26-8.
This section describes how to parallel program and verify Flash Program memory, EEPROM
D a t a
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/6450A/6450P. Pulses are
assumed to be at least 250 ns unless otherwise noted.
Part
ATmega165A/165PA
ATmega325A/325PA
ATmega3250A/3250PA
ATmega645A/645P
ATmega6450A/6450P
8K words (16Kbytes)
EEPROM Size
Flash Size
512bytes
m e m o r y ,
Device and JTAG ID
No. of Words in a Page and No. of Pages in the Flash
No. of Words in a Page and No. of Pages in the EEPROM
M e m o r y
0x000
0x1E
0x1E
0x1E
0x1E
0x1E
Page Size
Page Size
64 words
4 bytes
Signature Bytes
0x001
0x94
0x95
0x95
0x96
0x96
L o c k
PCWORD
PCWORD
EEA[1:0]
PC[5:0]
0x002
b i t s ,
0x0D
0x0D
0x07
0x0E
0x0E
No. of Pages
No. of Pages
a n d
Part Number
128
128
950D
950E
960D
960E
9407
F u s e
PCPAGE
EEA[8:2]
PCPAGE
PC[12:6]
JTAG
Table
b i t s
Manufacture ID
26-6.
8285B–AVR–03/11
0x1F
0x1F
0x1F
0x1F
0x1F
EEAMSB
i n
PCMSB
12
8
t h e