ATmega325 Atmel Corporation, ATmega325 Datasheet - Page 225

• Manufacturer Part Number: ATmega325
• Manufacturer: Atmel Corporation

Specifications of ATmega325

• Flash (kbytes): 32 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

25.3.1
25.3.2
25.3.2.1
25.3.2.2
25.3.2.3
25.3.3
2570N–AVR–05/11
Bypass Register
Device Identification Register
Reset Register
Version
Part Number
Manufacturer ID
The Bypass Register consists of a single Shift Register stage. When the Bypass Register is
selected as path between TDI and TDO, the register is reset to 0 when leaving the Capture-DR
controller state. The Bypass Register can be used to shorten the scan chain on a system when
the other devices are to be tested.
Figure 25-1
Figure 25-1. The Format of the Device Identification Register
Version is a 4-bit number identifying the revision of the component. The JTAG version number
follows the revision of the device. Revision A is 0x0, revision B is 0x1 and so on.
The part number is a 16-bit code identifying the component. The JTAG Part Number for Atmel
ATmega325/3250/645/6450 is listed in
Table 25-1.
The Manufacturer ID is a 11-bit code identifying the manufacturer. The JTAG manufacturer ID
for ATMEL is listed in
Table 25-2.
The Reset Register is a test Data Register used to reset the part. Since the AVR tri-states Port
Pins when reset, the Reset Register can also replace the function of the unimplemented optional
JTAG instruction HIGHZ.
A high value in the Reset Register corresponds to pulling the external Reset low. The part is
reset as long as there is a high value present in the Reset Register. Depending on the fuse set-
tings for the clock options, the part will remain reset for a reset time-out period (refer to
Bit
Device ID
Part Number
ATmega325
ATmega3250
ATmega645
ATmega6450
Manufacturer
ATMEL
MSB
31
shows the structure of the Device Identification Register.
Version
AVR JTAG Part Number
Manufacturer ID
4 bits
28
Table
27
25-2.
Part Number
16 bits
Table
ATmega325/3250/645/6450
25-1.
JTAG Manufacturer ID (Hex)
JTAG Part Number (Hex)
12
11
0x9505
0x9506
0x9605
0x9606
Manufacturer ID
0x01F
11 bits
1
1-bit
LSB
1
0
“Clock
225