Atmel Xplained Evaluation Board AT32UC3A3-XPLD AT32UC3A3-XPLD Data Sheet

32072H–AVR32–10/2012

This instruction allows a programmer to completely erase all nonvolatile memories in a chip.
This will also clear any security bits that are set, so the device can be accessed normally. In
devices without non-volatile memories this instruction does nothing, and appears to complete
immediately.

The erasing of non-volatile memories starts as soon as the CHIP_ERASE instruction is selected.
The CHIP_ERASE instruction selects a 1 bit bypass data register.

A chip erase operation should be performed as:

1.

Reset the system and stop the CPU from executing.

2.

Select the IR Scan path.

3.

In Capture-IR: The IR output value is latched into the shift register.

4.

In Shift-IR: The instruction register is shifted by the TCK input.

5.

Check the busy bit that was scanned out during Shift-IR. If the busy bit was set goto 2.

6.

Return to Run-Test/Idle.

This instruction allows a programmer to easily stop the CPU to ensure that it does not execute
invalid code during programming.

This instruction selects a 1-bit halt register. Setting this bit to one resets the device and halts the
CPU. Setting this bit to zero resets the device and releases the CPU to run normally. The value
shifted out from the data register is one if the CPU is halted. 

The HALT instruction can be used in 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.

Return to Run-Test/Idle.

5.

Select the DR Scan path.

DR Size

Device specific.

DR input value

Device specific.

DR output value

Device specific.

Table 35-24. AVR_RESET Details (Continued)

Table 35-25. CHIP_ERASE Details

IR input value

01111 (0x0F)

IR output value

p0b01

Where b is the busy bit.

DR Size

1 bit

DR input value

x

DR output value

0