ATMEGA325P-20MU Atmel, ATMEGA325P-20MU Datasheet - Page 231

• Manufacturer Part Number: ATMEGA325P-20MU
• Description: IC MCU AVR 32K FLASH 64-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA325P-20MU

• 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): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-MLF®, 64-QFN
• 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: 54
• 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: 10 bit, 8 Channel
• For Use With: ATSTK600-TQFP64 - STK600 SOCKET/ADAPTER 64-TQFP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ATMEGA325P-16MU; ATMEGA325P-16MU

23.3.4
23.4
23.4.1
23.4.2
8023F–AVR–07/09
Boundary-scan Specific JTAG Instructions
Boundary-scan Chain
EXTEST; 0x0
IDCODE; 0x1
Figure 23-1. Reset Register
The Boundary-scan Chain has the capability of driving and observing the logic levels on the dig-
ital I/O pins, as well as the boundary between digital and analog logic for analog circuitry having
off-chip connections.
See
The Instruction Register is 4-bit wide, supporting up to 16 instructions. Listed below are the
JTAG instructions useful for Boundary-scan operation. Note that the optional HIGHZ instruction
is not implemented, but all outputs with tri-state capability can be set in high-impedant state by
using the AVR_RESET instruction, since the initial state for all port pins is tri-state.
As a definition in this data sheet, the LSB is shifted in and out first for all Shift Registers.
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.
Mandatory JTAG instruction for selecting the Boundary-scan Chain as Data Register for testing
circuitry external to the AVR package. For port-pins, Pull-up Disable, Output Control, Output
Data, and Input Data are all accessible in the scan chain. For Analog circuits having off-chip
connections, the interface between the analog and the digital logic is in the scan chain. The con-
tents of the latched outputs of the Boundary-scan chain is driven out as soon as the JTAG IR-
Register is loaded with the EXTEST instruction.
The active states are:
• Capture-DR: Data on the external pins are sampled into the Boundary-scan Chain.
• Shift-DR: The Internal Scan Chain is shifted by the TCK input.
• Update-DR: Data from the scan chain is applied to output pins.
Optional JTAG instruction selecting the 32 bit ID-Register as Data Register. The ID-Register
consists of a version number, a device number and the manufacturer code chosen by JEDEC.
This is the default instruction after power-up.
”Boundary-scan Chain” on page 232
From Other Internal and
External Reset Sources
From
ClockDR · AVR_RESET
TDI
D
for a complete description.
Q
TDO
To
ATmega325P/3250P
Internal reset
231