ATMEGA3250P-20AU Atmel, ATMEGA3250P-20AU Datasheet - Page 291

• Manufacturer Part Number: ATMEGA3250P-20AU
• Description: IC MCU AVR 32K FLASH 100-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA3250P-20AU

• 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: 69
• 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): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TQFP, 100-VQFP
• Processor Series: ATMEGA32x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: SPI/UART/USI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 69
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• For Use With: ATSTK600-TQFP100 - STK600 SOCKET/ADAPTER 100-TQFP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRISP2 - PROGRAMMER AVR IN SYSTEMATSTK504 - STARTER KIT AVR EXP MOD 100P LCD
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ATMEGA3250P-16AU; ATMEGA3250P-16AU

25.8
25.8.1
8023F–AVR–07/09
Programming via the JTAG Interface
Programming Specific JTAG Instructions
Programming through the JTAG interface requires control of the four JTAG specific pins: TCK,
TMS, TDI, and TDO. Control of the reset and clock pins is not required.
To be able to use the JTAG interface, the JTAGEN Fuse must be programmed. The device is
default shipped with the fuse programmed. In addition, the JTD bit in MCUCR must be cleared.
Alternatively, if the JTD bit is set, the external reset can be forced low. Then, the JTD bit will be
cleared after two chip clocks, and the JTAG pins are available for programming. This provides a
means of using the JTAG pins as normal port pins in Running mode while still allowing In-Sys-
tem Programming via the JTAG interface. Note that this technique can not be used when using
the JTAG pins for Boundary-scan or On-chip Debug. In these cases the JTAG pins must be ded-
icated for this purpose.
During programming the clock frequency of the TCK Input must be less than the maximum fre-
quency of the chip. The System Clock Prescaler can not be used to divide the TCK Clock Input
into a sufficiently low frequency.
As a definition in this data sheet, the LSB is shifted in and out first of all Shift Registers.
The Instruction Register is 4-bit wide, supporting up to 16 instructions. The JTAG instructions
useful for programming are listed below.
The OPCODE for each instruction is shown behind the instruction name in hex format. The text
describes which Data Register is selected as path between TDI and TDO for each instruction.
The Run-Test/Idle state of the TAP controller is used to generate internal clocks. It can also be
used as an idle state between JTAG sequences. The state machine sequence for changing the
instruction word is shown in
Figure
25-13.
ATmega325P/3250P
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