Atmel Evaluation Kit for AT32uC3A0512, 32-Bit AVR Microcontroller Atmel ATEVK1105 ATEVK1105 Data Sheet
Product codes
ATEVK1105
748
AT32UC3A
Memory can be written while the CPU is executing, which can be utilized for debug purposes.
When downloading a new program, the JTAG HALT instruction should be used to freeze the
CPU, to prevent partially downloaded code from being executed.
36.7
JTAG Instruction Summary
The implemented JTAG instructions in the AVR32 are shown in the table below.
36.7.1
Security restrictions
When the security fuse in the Flash is programmed, the following JTAG instructions are
restricted:
• NEXUS_ACCESS
• MEMORY_WORD_ACCESS
• MEMORY_BLOCK_ACCESS
• MEMORY_SIZED_ACCESS
• MEMORY_WORD_ACCESS
• MEMORY_BLOCK_ACCESS
• MEMORY_SIZED_ACCESS
Table 36-2.
JTAG Instruction Summary
Instruction
OPCODE
OPCODE
Instruction
Description
Page
0x01
IDCODE
Select the 32-bit ID register as data register.
0x02
SAMPLE_PRELOAD
Take a snapshot of external pin values without affecting system
operation.
0x03
EXTEST
Select boundary scan chain as data register for testing circuitry
external to the device.
0x04
INTEST
Select boundary scan chain for internal testing of the device.
0x06
CLAMP
Bypass device through Bypass register, while driving outputs from
boundary scan register.
0x0C
AVR_RESET
Apply or remove a static reset to the device
0x0F
CHIP_ERASE
Erase the device
0x10
NEXUS_ACCESS
Select the SAB Address and Data registers as data register for the
TAP. The registers are accessed in Nexus mode.
0x11
MEMORY_WORD_ACCESS
Select the SAB Address and Data registers as data register for the
TAP.
0x12
MEMORY_BLOCK_ACCESS
Select the SAB Data register as data register for the TAP. The
address is auto-incremented.
0x13
CANCEL_ACCESS
Cancel an ongoing Nexus or Memory access.
0x14
MEMORY_SERVICE
Select the SAB Address and Data registers as data register for the
TAP. The registers are accessed in Memory Service mode.
0x15
MEMORY_SIZED_ACCESS
Select the SAB Address and Data registers as data register for the
TAP.
0x17
SYNC
Synchronization counter
0x1C
HALT
Halt the CPU for safe programming.
0x1F
BYPASS
Bypass this device through the bypass register.
Others
N/A
Acts as BYPASS
32058K
AVR32-01/12