Datasheet

702
32133D–11/2011
UC3D
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
6. In Capture-DR: The Data on the external pins are sampled into the boundary-scan
chain.
7. In Shift-DR: The boundary-scan chain is shifted by the TCK input.
8. Return to Run-Test/Idle.
31.6.2.3 EXTEST
This instruction selects the boundary-scan chain as Data Register for testing circuitry external to
the 32-bit AVR package. The contents 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.
Starting in Run-Test/Idle, the EXTEST instruction is accessed the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. In Update-IR: The data from the boundary-scan chain is applied to the output pins.
5. Return to Run-Test/Idle.
6. Select the DR Scan path.
7. In Capture-DR: The data on the external pins is sampled into the boundary-scan chain.
8. In Shift-DR: The boundary-scan chain is shifted by the TCK input.
9. In Update-DR: The data from the scan chain is applied to the output pins.
10. Return to Run-Test/Idle.
Table 31-42. SAMPLE_PRELOAD Details
Instructions Details
IR input value 00010 (0x02)
IR output value p0001
DR Size Depending on boundary-scan chain, see BSDL-file.
DR input value Depending on boundary-scan chain, see BSDL-file.
DR output value Depending on boundary-scan chain, see BSDL-file.
Table 31-43. EXTEST Details
Instructions Details
IR input value 00011 (0x03)
IR output value p0001
DR Size Depending on boundary-scan chain, see BSDL-file.
DR input value Depending on boundary-scan chain, see BSDL-file.
DR output value Depending on boundary-scan chain, see BSDL-file.