ATEVK1105 Atmel, ATEVK1105 Datasheet - Page 745

• Manufacturer Part Number: ATEVK1105
• Description: KIT EVAL FOR AT32UC3A0
• Manufacturer: Atmel
• Series: AVR®32r
• Type: MCUr

Specifications of ATEVK1105

• Contents: Evaluation Board, Software and Documentation
• Processor To Be Evaluated: AT32UC3A0512
• Processor Series: AVR
• Data Bus Width: 32 bit
• Interface Type: USART, TWI, USB, SPI, Ethernet
• Operating Supply Voltage: 3.3 V
• Silicon Manufacturer: Atmel
• Core Architecture: AVR
• Core Sub-architecture: AVR UC3
• Silicon Core Number: AT32UC3A0512
• Silicon Family Name: AVR
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT32UC3A0
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 36-3. Scanning in JTAG instruction
36.6.2.2
36.6.3
32058J–AVR32–04/11
Boundary-Scan
Scanning in/out data
TCK
TAP State
TMS
TDI
TDO
TLR
At the TMS input, apply the sequence 1, 0, 0 at the rising edges of TCK to enter the Shift Data
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. 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.
Apply the TMS sequence 1, 1, 0 to re-enter the Run-Test/Idle state. If the selected Data 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.
As shown in the state diagram, the Run-Test/Idle state need not be entered between selecting
JTAG instruction and using Data Registers.
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. At system level, all ICs having JTAG capabilities are connected serially by
the TDI/TDO signals to form a long shift register. An external controller sets up the devices to
drive values at their output pins, and observe the input values received from other devices. The
controller compares the received data with the expected result. In this way, Boundary-Scan pro-
vides a mechanism for testing interconnections and integrity of components on Printed Circuits
Boards by using the 4 TAP signals only.
The four IEEE 1149.1 defined mandatory JTAG instructions IDCODE, BYPASS, SAMPLE/PRE-
LOAD, and EXTEST can be used for testing the Printed Circuit Board. Initial scanning of the
data register path will show the ID-code of the device, since IDCODE is the default JTAG
instruction. It may be desirable to have the AVR32 device in reset during test mode. If not reset,
inputs to the device may be determined by the scan operations, and the internal software may
be in an undetermined state when exiting the test mode. Entering reset, the outputs of any Port
Pin will instantly enter the high impedance state, making the HIGHZ instruction redundant. If
needed, the BYPASS instruction can be issued to make the shortest possible scan chain
through the device. The device can be set in the reset state either by pulling the external
RESETn pin low, or issuing the AVR_RESET instruction with appropriate setting of the Reset
Data Register.
The EXTEST instruction is used for sampling external pins and loading output pins with data.
The data from the output latch will be driven out on the pins as soon as the EXTEST instruction
is loaded into the JTAG IR-register. Therefore, the SAMPLE/PRELOAD should also be used for
setting initial values to the scan ring, to avoid damaging the board when issuing the EXTEST
RTI
SelDR SelIR CapIR ShIR
Instruction
ImplDefined
Ex1IR UpdIR RTI
AT32UC3A
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