ATMEL AVR067 User Manual

http://www.BDTIC.com/ATMEL

AVR067: JTAGICE mkII

Communication Protocol

Features

• Commands sent from AVR Studio to JTAGICE mkII

• Replies sent from JTAGICE mkII to AVR Studio

• Configurable Parameters

• Different Memory Types

• Special Characters and Packet Formats for Packet Synchronization and

Error Control

• Break Point Handling in JTAGICE mkII (tinyAVR / megaAVR devices only)

1 Introduction

This document describes the communication protocol used between AVR Studio
and JTAGICE mkII. The purpose of this document is to enable third party vendors
to design their own front-end to the JTAGICE mkII.

8-bit
Microcontrollers

Application Note

Rev. 2587D-AVR-11/09

http://www.BDTIC.com/ATMEL

2 Theory of operation

The communication protocol operates in a master – slave environment, AVR Studio
being the master and JTAGICE mkII being the slave.

The JTAGICE mkII slave is always operating in one of three states (with
enumeration):

1. STOPPED

2. RUNNING

3. PROGRAMMING
Some commands can only be executed while the slave is in STOPPED mode, others

may be allowed in all modes. The details are described for each different command.
Events are messages sent from the slave with no prior commands given from the

master.
Serial communication is asynchronous by nature, so is the JTAGICE mkII protocol. All

commands and responses have tokens and CRC checks included enabling the
receiver to verify the validity of the received message.

This transport protocol guarantees that every packet that is received is verified
correctly, but it does not guarantee that every packet is received. Retransmission and
lost packets are to be handled by the application layer, not the transmission layer.
When USB is used, the hardware layer handles retransmission automatically. This is
not the case with RS232.

The protocol is “Little Endean”, LSB is always transferred first in memory addresses.

2.1 USB and RS-232 Connection

The JTAGICE mkII has both a USB and an RS-232 interface for connecting to a host
computer. They share the same message format (see section 3).

USB is preferred due to speed.

2.1.1 RS-232 Connection

The RS-232 connection’s power-on settings are 19,200 bps, 8N1, no handshake.
However, using the Set Parameter command and the Baud rate parameter, the baud
rate can be changed.

2.1.2 USB Connection

The JTAGICE mkII has a USB port capable of USB full-speed connection (12Mbps).
In addition to data transfer, the USB cable can also supply power to the emulator, so

no external power is required. After enumeration, the emulator can draw up to 500mA
from the USB hub.

2.1.3 USB Configuration

The JTAGICE mkII has one configuration with one interface containing two bulk
transfer endpoints. The USB descriptors can be found in section 7.

The JTAGICE mkII messages are transferred through the bulk endpoints. Maximum
packet size is shown in the endpoint descriptors.

2

AVR067

2587D-AVR-11/09

3 Message Format

http://www.BDTIC.com/ATMEL

In addition to the framing mechanisms supplied by the JTAGICE mkII frame format,
the emulator uses short packets (both IN and OUT endpoints) to indicate which USB
packet is the last one in a JTAGEICE mkII frame. The host driver must also support
short packets.

All commands, responses and events share a common message format:
<MESSAGE_START, SEQUENCE_NUMBER, MESSAGE_SIZE, TOKEN,

MESSAGE_BODY, CRC>

Table 3-1. Parameters of messages.

Parameter Name Usage Format

MESSAGE_START ASCII 27 (ESC character) [BYTE]
SEQUENCE_NUMBER

MESSAGE_SIZE Size of the message body in bytes [BYTE]*4, LSB first
TOKEN

MESSAGE_BODY Message body [BYTE]*MESSAGE_SIZE
CRC

First byte of the message body is always the MESSAGE_ID. The size of the
MESSAGE_BODY is at least 1 byte.

Incremented by one for each
message sent. Wraps to zero after
0xFFFE. 0xFFFF is reserved for
(asynchronous) EVENTS.

ASCII 14, making the protocol more
robust.

Uses all characters in message
including MESSAGE_START and
MESSAGE_BODY.

[BYTE]*2, LSB first.

[BYTE]

[BYTE]*2

AVR067

4 Message parsing

4.1 Introduction

2587D-AVR-11/09

• Messages use MESSAGE_ID in the range from 0x01 to 0x3F

• Success responses use MESSAGE_ID in the range from 0x80 to 0x9F

• Failure responses use MESSAGE_ID in the range from 0xA0 to 0xBF

• Events use MESSAGE_ID in the range from 0xE0 to 0xFF

• Message start is ASCII 27 (0x1B), not to be changed.

• Token is ASCII 14 (0x0E), not to be changed.

Messages either way should be read as a byte stream by a state machine. Every time
a MESSAGE_START character occurs, the state machine starts to decode the
message, either completing the message or falling out of the byte stream if a
message rule is violated.

Messages can come in any order and there is no specific timing regarding required
timeframes between commands. The emulator implements a message queue, when
the state machine has parsed and verified a complete message it is serialized and put
on a message queue. The emulator executes the messages in the sequence found

3

http://www.BDTIC.com/ATMEL

on the queue. Responses to the messages are given when they are processed by the
emulator.

The same state machine is used for both RS232 and USB transmission. An interrupt
routine on the communication control processor in the JTAGICE mkII reads the
appropriate UART and puts the incoming data in a FIFO implemented in SRAM. The
state machine reads and parses the data from the FIFO.

4.2 Common State Machine Implementation

Figure 4-1. State Diagram

Char < > A S CII 27

E: CRC byte 0

C: nmb char ==

MESSAGE_SIZE

E: New char

C: nmb char <

MESSAGE_SIZE

CRC

E: New char

Get D a ta

E: CR C b yte 1

C: CRC illegal
A: Clear buffers
update statistics

E: CR C b yte 1

C: CRC legal

A: Store complete

message in queue.

E: Legal Token
C: Message Size > 0
A: Start timeout timer

Start

E: Illegal Token

A: Clear message

buffer, update illegal

message statistics

Get Token

E: Cha r = = A SCII27

A: Start timeout timer

A: Send Timeout

response to master

E: Timeout

A: Send Timeout

Response to Master

E: Message Size

Complete

A: Start Timeout Timer

E: Timeout

Get

Message

Size

Read bytes 0-2

Get

Sequence

Number

Read bytes 0-1

E: Message ID read

A: Start Timeout Timer

4

AVR067

2587D-AVR-11/09

http://www.BDTIC.com/ATMEL

AVR067

Table 4-1. State table. Gray fields represent “message failed”, non grayed fields are “message valid”.

Current State Event Condition Action Next State

Start

Get Sequence
Number

Get Message
Size

Get Token

Get Data

Get CRC

Read character from inbuf Char == ASCII 27 Start timeout timer

Read character from inbuf Char <> ASCII 27 None Start
Read character from inbuf

Read character from inbuf

Timeout None Update message statistics Start
Read character from inbuf

Read character from inbuf

Timeout None Update message statistics Start
Read character from inbuf Char == ASCII 14 Start timeout timer

Read character from inbuf Char <> ASCII 14 Update message statistics

Timeout None Update message statistics Start
Read character from inbuf

Read character from inbuf

Timeout None Update message statistics Start
Read character from inbuf CRC Byte Count == 2

Read character from inbuf CRC Byte Count == 2

Read character from inbuf CRC Byte Count < 2 Start timeout timer Get CRC
Timeout None Update message statistics Start

Sequence Number Byte
Counter == 2

Sequence Number Byte
Counter < 2

Message Size Byte
Counter < 4

Message Size Byte
Counter ==4

Nmb char read ==
MESSAGE_SIZE

Nmb char read <
MESSAGE_SIZE

CRC OK

CRC NOT OK

Start timeout timer

Start timeout timer

Start timeout timer Get Message Size

Start timeout timer
Calculate MESSAGE_SIZE

Stop timeout timer

Start timeout timer Get CRC

Start timeout timer Get Data

Calculate CRC
Update message statistics
Execute command
Stop timeout timer

Calculate CRC
Update message statistics
Stop timeout timer

Get Sequence
Number

Get Message Size

Get Sequence
Number

Get Token

Get Data

Start

Start

Start

5 Commands and responses

5.1 Master Commands

5.1.1 Sign off (CMND_SIGN_OFF: 0x00)

The master issues this command when it terminates a debugging session.
Slave state: All states.

2587D-AVR-11/09

5

http://www.BDTIC.com/ATMEL

Table 5-1. Message Format

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 0x01
TOKEN ASCII 14
MESSAGE_BODY None
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MESSAGE_ID>

Table 5-2. Parameters

Parameter Name Usage Format

MESSAGE_ID 0x00 (CMND_SIGN_OFF) [BYTE]

Table 5-3. Response

Parameter Name Description

RSP_OK The command was executed.
RSP_FAILED

The JTAGICE mkII is there, but it did not understand
the command.

6

AVR067

2587D-AVR-11/09

http://www.BDTIC.com/ATMEL

5.1.2 Check if Emulator is present (CMND_GET_SIGN_ON: 0x01)

The master uses this command to see if an emulator is attached and alive.
Slave state: All states.

Table 5-4. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 0x01
TOKEN ASCII 14
MESSAGE_BODY None
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MESSAGE_ID>

AVR067

Table 5-5. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x01 (CMND_GET_SIGN_ON) [BYTE]

Table 5-6. Response.

Parameter Name Description

RSP_SIGN_ON

RSP_FAILED

TIMEOUT

Garbage

Contains sign on string for JTAGICE mkII.
Compatibility issues with other emulators must be
resolved.

Sign on (RSP_SIGN_ON : 0x86)
The JTAGICE mkII is there, but it did not understand

the command.
No slave response within the defined timeout time.

The slave is either not there, or it is not turned on.
If serial communication is used, HW error UART

configuration error (wrong baud rate, parity bit setting
etc)

If USB communication is used, HW error.

2587D-AVR-11/09

7

http://www.BDTIC.com/ATMEL

5.1.3 Write Emulator Parameter (CMND_SET_PARAMETER: 0x02)

The emulator hosts a number of set-up parameters. This command is used to write all
parameters. The parameter ID identifies the parameter written.

Slave state: Depending on the parameter.

Table 5-7. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE The size of the MESSAGE_BODY in bytes.
TOKEN ASCII 14
MESSAGE_BODY See below
CRC 2-byte CRC.

The message body consists of:
<MESSAGE_ID, PARAMETER_ID, PARAMETER_VALUE>

Table 5-8. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x02 (CMND_SET_PARAMETER) [BYTE]
PARAMETER_ID Parameter ID [BYTE]
PARAMETER_VALUE Parameter value, can be of any size

[BYTE] * N,
LSB first if
applicable.

Table 5-9. Response.

Parameter Name Description

RSP_OK The parameter is written OK.
RSP_FAILED

RSP_ILLEGAL_PARAMETER

RSP_ILLEGAL_VALUE The given value was invalid or out or range
RSP_ILLEGAL_EMULATOR_MODE

Timeout No response from the slave within the timeout time.

The command was not understood by the JTAGICE
mkII

The JTAGICE mkII does not support the selected
parameter (AVR Studio 4 – JTAGICE mkII FW
incompatibility).

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

The parameter description is found in a later section in this document.

8

AVR067

2587D-AVR-11/09

5.1.4 Read Emulator Parameter (CMND_GET_PARAMETER: 0x03)

http://www.BDTIC.com/ATMEL

Reads emulator set-up parameters back to AVR Studio. Parameter descriptions
found in a later section in this document.

Slave state: Depending on the parameter.

Table 5-10. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 0x02
TOKEN ASCII 14
MESSAGE_BODY Defined below
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MESSAGE_ID, PARAMETER_ID>

Table 5-11. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x03 (CMND_GET_PARAMETER) [BYTE]
PARAMETER_ID The requested emulator parameter [BYTE]

AVR067

Table 5-12. Response.

Parameter Name Description

RSP_PARAMETER Returns the requested parameter.

RSP_FAILED

RSP_ILLEGAL_PARAMETER

RSP_ILLEGAL_EMULATOR_MODE

Timeout No response from the slave within the timeout time.

5.1.5 Write Memory (CMND_WRITE_MEMORY: 0x04)

Write a memory block to any address in any memory area.
Slave state: STOPPED.

Table 5-13. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE The size of the MESSAGE_BODY in bytes.

Parameter return (RSP_PARAMETER : 0x81)
The command was not understood by the JTAGICE

mkII
The JTAGICE mkII does not support the selected

parameter (AVR Studio 4 – JTAGICE mkII FW
incompatibility).

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

2587D-AVR-11/09

9

http://www.BDTIC.com/ATMEL

Parameter Name Description

TOKEN ASCII 14
MESSAGE_BODY See below
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MESSAGE_ID, MEMORY_TYPE, BYTE_COUNT, START_ADDRESS, DATA>

Table 5-14. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x04 (CMND_WRITE_MEMORY) [BYTE]
MEMORY_TYPE

BYTE_COUNT Number of bytes to be written

START_ADDRESS Start memory address

DATA The data

Memory type (Flash, SRAM,
EEPROM...)

[BYTE]

[BYTE]*4 LSB
first

[BYTE]*4 LSB
first

[BYTE] *
BYTE_COUNT

Definitions and parameter values of the different memory types are found in the
Memory Types section.

Table 5-15. Response.

Parameter Name Description

RSP_OK The memory is written OK.
RSP_FAILED

RSP_ILLEGAL_MEMORY_TYPE

RSP_ILLEGAL_MEMORY_RANGE

RSP_ILLEGAL_EMULATOR_MODE

RSP_ILLEGAL_MCU_STATE

Timeout No response from the slave within the timeout time.

The command was not understood by the JTAGICE
mkII

The JTAGICE mkII does not support the selected
memory.

The memory write was outside the bounds of the
selected memory area.

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

The operation cannot be performed with the target
MCU in its current state.

10

AVR067

2587D-AVR-11/09

http://www.BDTIC.com/ATMEL

5.1.6 Read Memory (CMND_READ_MEMORY: 0x05)

Read a memory block from any address in any memory area.
Slave state: STOPPED

Table 5-16. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 10 bytes.
TOKEN ASCII 14
MESSAGE_BODY See below
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MEMORY_TYPE, BYTE_COUNT, START_ADDRESS>

AVR067

Table 5-17. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x05 (CMND_READ_MEMORY) [BYTE]
MEMORY_TYPE

BYTE_COUNT Number of bytes to be read

START_ADDRESS Start memory address

Memory type (Flash, SRAM,
EEPROM...)

[BYTE]

[BYTE]*4 LSB
first

[BYTE]*4 LSB
first

Definitions and parameter values of the different memory types are found in the
Memory Types section.

Table 5-18. Response.

Parameter Name Description

RSP_MEMORY The memory is read OK.

Memory read (RSP_MEMORY : 0x82)

RSP_FAILED

RSP_ILLEGAL_MEMORY_TYPE

RSP_ILLEGAL_MEMORY_RANGE

RSP_ILLEGAL_EMULATOR_MODE

The command was not understood by the JTAGICE
mkII

The JTAGICE mkII does not support the selected
memory.

The memory write was outside the bounds of the
selected memory area.

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

2587D-AVR-11/09

11

http://www.BDTIC.com/ATMEL

Parameter Name Description

RSP_ILLEGAL_MCU_STATE

Timeout No response from the slave within the timeout time.

5.1.7 Write Program Counter (CMND_WRITE_PC: 0x06)

Writes the AVR Program Counter.
Slave state: STOPPED.

Table 5-19. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 5
TOKEN ASCII 14
MESSAGE_BODY See below.
CRC 2-byte CRC.

The operation cannot be performed with the target
MCU in its current state.

The MESSAGE_BODY consists of:
<MESSAGE_ID, PROGRAM_COUNTER>

Table 5-20. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x06 (CMND_WRITE_PC) [BYTE]
PROGRAM_COUNTER Program Counter

[BYTE]*4 LSB
first.

Table 5-21. Response.

Parameter Name Description

RSP_OK The program counter was written OK.
RSP_FAILED

RSP_ILLEGAL_EMULATOR_MODE

RSP_ILLEGAL_MCU_STATE

Timeout No response from the slave within the timeout time.

The command was not understood by the JTAGICE
mkII

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

The operation cannot be performed with the target
MCU in its current state.

5.1.8 Read Program Counter (CMND_READ_PC: 0x07)

Reads the AVR Program Counter.

12

AVR067

2587D-AVR-11/09

http://www.BDTIC.com/ATMEL

AVR067

Slave state: STOPPED.

Table 5-22. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 1
TOKEN ASCII 14
MESSAGE_BODY See below.
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MESSAGE_ID>

Table 5-23. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x07 (CMND_READ_PC) [BYTE]

Table 5-24. Response.

Parameter Name Description

RSP_PC The program counter is returned.

Program Counter Read (RSP_PC : 0x84)

RSP_FAILED

RSP_ILLEGAL_EMULATOR_MODE

RSP_ILLEGAL_MCU_STATE

Timeout No response from the slave within the timeout time.

The command was not understood by the JTAGICE
mkII

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

The operation cannot be performed with the target
MCU in its current state.

2587D-AVR-11/09

13

http://www.BDTIC.com/ATMEL

5.1.9 Start Program Execution (CMND_GO: 0x08)

Starts program execution at current Program Counter address.
Slave state: STOPPED or RUNNING. When the command is executed the state

either changes to or remains in RUNNING.

Table 5-25. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 1
TOKEN ASCII 14
MESSAGE_BODY None
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
< MESSAGE_ID >

Table 5-26. Parameters.

Parameter Name Usage Format

MESSAGE_ID CMND_GO : 0x08 [BYTE]

Table 5-27. Response.

Parameter Name Description

RSP_OK The command was executed.
RSP_FAILED

RSP_ILLEGAL_EMULATOR_MODE

Timeout No response from the slave within the timeout time.

5.1.10 Single Step (CMND_SINGLE_STEP: 0x09)

Starts one-step execution at current Program Counter address.
Slave state: STOPPED. After execution the slave is in RUNNING state until it hits the

next breakpoint. Then a Break Event is issued, and the slave returns to STOPPED
state.

The command was not understood by the JTAGICE
mkII

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

Table 5-28. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)

14

AVR067

2587D-AVR-11/09

http://www.BDTIC.com/ATMEL

Parameter Name Description

SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 3
TOKEN ASCII 14
MESSAGE_BODY High level or low level flag, see below.
CRC 2-byte CRC.

AVR067

The MESSAGE_BODY consists of:
<MESSAGE_ID, FLAG>

Table 5-29. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x09 (CMND_SINGLE_STEP) [BYTE]
FLAG 0x01 : Low level

0x02 : High level.

STEP_MODE 0x00: STEP_OVER

0x01: STEP_INTO
0x02: STEP_OUT

[BYTE]

[BYTE]

Table 5-30. Response.

Parameter Name Description

RSP_OK The command is executed.
RSP_FAILED

RSP_ILLEGAL_EMULATOR_MODE

RSP_ILLEGAL_MCU_STATE

Timeout No response from the slave within the timeout time.

5.1.11 Stop Program Execution (CMND_FORCED_STOP: 0x0A)

Stops program execution.
Slave state: STOPPED or RUNNING. After execution of the command the slave is in

STOPPED state.

Table 5-31. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 2 Bytes
TOKEN ASCII 14
MESSAGE_BODY See below
CRC 2-byte CRC.

The command was not understood by the JTAGICE
mkII

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

The operation cannot be performed with the target
MCU in its current state.

2587D-AVR-11/09

15

http://www.BDTIC.com/ATMEL

The MESSAGE_BODY consists of:
<MESSAGE_ID, MODE>

Table 5-32. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x0A (CMND_FORCED_STOP) [BYTE]
MODE 0x01: LOW LEVEL

0x02: HIGH LEVEL
(stops at next high level statement)

Table 5-33. Response.

Parameter Name Description

RSP_OK The command is executed.
RSP_FAILED

RSP_ILLEGAL_EMULATOR_MODE

Timeout No response from the slave within the timeout time.

The command was not understood by the JTAGICE
mkII

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

[BYTE]

5.1.12 Reset User Program (CMND_RESET: 0x0B)

Emulator performs all actions to restart program execution
Slave state: Any. If the slave is in RUNNING mode prior to this operation, the slave

will change to STOPPED state prior to the execution of this command

Table 5-34. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE Size of message body
TOKEN ASCII 14
MESSAGE_BODY See below

CRC 2-byte CRC.

High level or low level flag. High level typically
returns to main. Give a procedure. Give low level
reset with “run afterwards”.

16

AVR067

2587D-AVR-11/09

http://www.BDTIC.com/ATMEL

AVR067

The MESSAGE_BODY consists of:
<MESSAGE_ID, FLAG>

Table 5-35. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x0B (CMND_RESET) [BYTE]
FLAG 0x01: Low level

0x02: High level (reset, then run to
main)

0x04: Reset with debugWire
disable.

[BYTE]

Table 5-36. Response.

Parameter Name Description

RSP_OK The command is executed.
RSP_FAILED

RSP_ILLEGAL_EMULATOR_MODE

Timeout No response from the slave within the timeout time.

The command was not understood by the JTAGICE
mkII

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

5.1.13 Set Device Descriptor (CMND_SET_DEVICE_DESCRIPTOR: 0x0C)

Transmits all parameters relevant for a specific device set-up
Slave state: STOPPED.

Table 5-37. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE Size of message body
TOKEN ASCII 14
MESSAGE_BODY All parameters for a specific device set-up.
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MESSAGE_ID, PARAMETERS>

Table 5-38. Parameters.

Parameter Name Usage Format

MESSAGE_ID

0x0C
(CMND_SET_DEVICE_DESCRIPTOR)

[BYTE]

2587D-AVR-11/09

17

http://www.BDTIC.com/ATMEL

Parameter Name Usage Format

PARAMETERS

Table 5-39. Response.

Parameter Name Description

RSP_OK The command is executed.
RSP_FAILED

RSP_ILLEGAL_EMULATOR_MODE

RSP_ILLEGAL_MCU_STATE

Timeout No response from the slave within the timeout time.

5.1.14 Erase Page SPM (CMND_ERASEPAGE_SPM: 0x0D)

Erases a whole page in Flash memory

All parameters required to set up a
device in raw binary form, identical to the
JTAGICE descriptor.

The command was not understood by the JTAGICE
mkII

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

The operation cannot be performed with the target
MCU in its current state.

[BYTE] *
298

Slave state: STOPPED

Table 5-40. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
MESSAGE_ID 0x0D (CMND_ERASEPAGE_SPM)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 5
TOKEN ASCII 14
MESSAGE_BODY See below
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MESSAGE_ID, PAGE_ADDRESS>

Table 5-41. Parameters.

Parameter Name Usage Format

MESSAGE_ID

PAGE_ADDRESS Address to the page to be erased

0x0D
(CMND_ERASEPAGE_SPM)

[BYTE]

[BYTE]*4, LSB
first

Table 5-42. Response.

Parameter Name Description

18

AVR067

2587D-AVR-11/09

Parameter Name Description

http://www.BDTIC.com/ATMEL

RSP_OK The command is executed.
RSP_FAILED

RSP_ILLEGAL_EMULATOR_MODE

RSP_ILLEGAL_MCU_STATE

Timeout No response from the slave within the timeout time.

5.1.15 Get Sync (CMND_GET_SYNC 0x0F)

Sent from AVR Studio in order to regain synchronization with JTAGICE mkII, if lost

Table 5-43. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE 1
TOKEN ASCII 14
MESSAGE_BODY See below
CRC 2-byte CRC.

The command was not understood by the JTAGICE
mkII

The operation cannot be performed in this emulator
mode. (JTAG / debugWire).

The operation cannot be performed with the target
MCU in its current state.

AVR067

The MESSAGE_BODY consists of:
<MESSAGE_ID>

Table 5-44. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x0F (CMND_GET_SYNC) [BYTE]

Table 5-45. Response.

Parameter Name Description

RSP_OK The command is executed.
RSP_FAILED

Timeout No response from the slave within the timeout time.

5.1.16 Self test (CMND_SELFTEST: 0x10)

Makes the JTAGICE mkII perform self test and report back to the master.
Slave state: STOPPED

Table 5-46. Message Format.

Parameter Name Description

The command was not understood by the JTAGICE
mkII.

2587D-AVR-11/09

19

http://www.BDTIC.com/ATMEL

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character).
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE Size of message body.
TOKEN ASCII 14
MESSAGE_BODY Parameters for self test (choose what to test).
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MESSAGE_ID, FLAGS>

Table 5-47. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x10 (CMND_SELFTEST) [BYTE]
FLAGS

FLAGS identifying which tests to be
performed.

bit 7: internal tests (SRAM, FIFO…)
bit 6: <not used>
bit 5: <not used>
bit 4: <not used>
bit 3: STK500 RESET JUMPER

detector
bit 2: JTAG PUSH PULL
bit 1: debugWire Capacitance
bit 0: debugWire PUSH PULL

[BYTE]

Table 5-48. Response.

Parameter Name Description

RSP_SELFTEST The command is executed.

RSP_FAILED

RSP_ILLEGAL_EMULATOR_MODE

RSP_ILLEGAL_MCU_STATE

Timeout No response from the slave within the timeout time.

5.1.17 Set Breakpoint (CMND_SET_BREAK: 0x11)

Set a breakpoint. (For hardware breakpoints on megaAVR devices with JTAG
interface only, and software breakpoints)

Slave state: STOPPED

20

AVR067

Selftest (RSP_SELFTEST : 0x85)
The command was not understood by the JTAGICE

mkII.
The operation cannot be performed in this emulator

mode. (JTAG / debugWire).
The operation cannot be performed with the target

MCU in its current state.

2587D-AVR-11/09

http://www.BDTIC.com/ATMEL

AVR067

Table 5-49. Message Format.

Parameter Name Description

MESSAGE_START ASCII 27 (ESC character)
SEQUENCE_NUMBER Incremented for each packet sent.
MESSAGE_SIZE Size of message body
TOKEN ASCII 14
MESSAGE_BODY Breakpoint setting (see format below).
CRC 2-byte CRC.

The MESSAGE_BODY consists of:
<MESSAGE_ID, TYPE, NUMBER, ADDRESS, MODE>

Table 5-50. Parameters.

Parameter Name Usage Format

MESSAGE_ID 0x11 (CMND_SET_BREAK) [BYTE]
TYPE 0x01: program memory breakpoint

0x02: data breakpoint
0x03:mask for data breakpoint

NUMBER

ADDRESS Break address of mask value

MODE 0x00: Break on memory read

Breakpoint number, 0x01 to 0x04
(up to 4 breakpoints are supported

0x00 for SW BP

0x01: Break on memory write
0x02: Break on memory read or

write.
0x03: Program breakpoint

[BYTE]

[BYTE]

[BYTE] * 4,
LSB first

[BYTE]

2587D-AVR-11/09

21