ATmega644P Atmel Corporation, ATmega644P Datasheet - Page 263

• Manufacturer Part Number: ATmega644P
• Manufacturer: Atmel Corporation

Specifications of ATmega644P

• Flash (kbytes): 64 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 32
• Usb Speed: No
• Usb Interface: No
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• 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): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• 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: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

21.5
21.6
8011O–AVR–07/10
Using the Boundary-scan Chain
Using the On-chip Debug System
• Apply the TMS sequence 1, 1, 0 to re-enter the Run-Test/Idle state. The instruction is latched
• At the TMS input, apply the sequence 1, 0, 0 at the rising edges of TCK to enter the Shift Data
• Apply the TMS sequence 1, 1, 0 to re-enter the Run-Test/Idle state. If the selected Data
As shown in the state diagram, the Run-Test/Idle state need not be entered between selecting
JTAG instruction and using Data Registers, and some JTAG instructions may select certain
functions to be performed in the Run-Test/Idle, making it unsuitable as an Idle state.
Note:
For detailed information on the JTAG specification, refer to the literature listed in
on page
A complete description of the Boundary-scan capabilities are given in the section
(JTAG) Boundary-scan” on page
As shown in
• A scan chain on the interface between the internal AVR CPU and the internal peripheral units.
• Break Point unit.
• Communication interface between the CPU and JTAG system.
All read or modify/write operations needed for implementing the Debugger are done by applying
AVR instructions via the internal AVR CPU Scan Chain. The CPU sends the result to an I/O
memory mapped location which is part of the communication interface between the CPU and the
JTAG system.
The Break Point Unit implements Break on Change of Program Flow, Single Step Break, two
Program Memory Break Points, and two combined Break Points. Together, the four Break
Points can be configured as either:
• 4 single Program Memory Break Points.
• 3 Single Program Memory Break Point + 1 single Data Memory Break Point.
• 2 single Program Memory Break Points + 2 single Data Memory Break Points.
• 2 single Program Memory Break Points + 1 Program Memory Break Point with mask (“range
• 2 single Program Memory Break Points + 1 Data Memory Break Point with mask (“range Break
onto the parallel output from the Shift Register path in the Update-IR state. The Exit-IR, Pause-
IR, and Exit2-IR states are only used for navigating the state machine.
Register – Shift-DR state. While in this state, upload the selected Data Register (selected by
the present JTAG instruction in the JTAG Instruction Register) from the TDI input at the rising
edge of TCK. In order to remain in the Shift-DR state, the TMS input must be held low during
input of all bits except the MSB. The MSB of the data is shifted in when this state is left by
setting TMS high. While the Data Register is shifted in from the TDI pin, the parallel inputs to
the Data Register captured in the Capture-DR state is shifted out on the TDO pin.
Register has a latched parallel-output, the latching takes place in the Update-DR state. The
Exit-DR, Pause-DR, and Exit2-DR states are only used for navigating the state machine.
Break Point”).
Point”).
Independent of the initial state of the TAP Controller, the Test-Logic-Reset state can always be
entered by holding TMS high for five TCK clock periods.
265.
Figure
21-1, the hardware support for On-chip Debugging consists mainly of
266.
ATmega164P/324P/644P
”Bibliography”
”IEEE 1149.1
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