8-bit
Microcontrollers
Application Note
Rev. 8015B-AVR-02/06
AVR069: AVRISP mkII Communication Protocol
Features
General commands
ISP commands
Return values
Parameters
1 Introduction
This document describes the AVRISP mkII protocol. The firmware is distributed
with AVR Studio 4.12 or later. Download the latest AVR Studio from the Atmel web
site,
.
The definition of all commands, responses, parameters and other defined values
can be found in chapter 6.1.
All device specific values can be found in the XML part description files. See
chapter 4 for how to find the parameter values for AVRISP mkII.
Figure 1-1.
AVRISP mkII
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2 USB Communication
The communication between the AVRISP mkII and the PC is done through its USB
interface. The USB interface utilizes two bulk endpoints; one IN and one OUT. The
USB descriptors can be found in chapter 6.2.
2.1 Packet Format
The PC sends commands to the AVRISP mkII, which responds with an answer. Each
command will generate an answer.
Both commands and answers can be larger than the maximum packet size for the
bulk endpoints, so a command or answer can be split into several IN/OUT packets. A
short packet
indicates the end of a command or answer.
The commands and their respective answers are described in chapter 3.
2.2 USB Driver
In order to communicate with the AVRISP mkII, a driver must be installed on the host
computer. A driver can be written from scratch or by using a driver development kit.
AVR Studio 4 bundles a USB driver licensed from Jungo (
www.jungo.com
). By
obtaining a license from Jungo, 3rd party software can access the same driver as
AVR Studio. The user can then use both AVR Studio and other tools without
changing drivers.
Note: Firmware upgrades for AVRISP mkII can only be uploaded with the dedicated upgrade
software bundled with AVR Studio. This requires that the driver supplied with AVR Studio to be
installed.
3 Commands
This section describes all commands that can be entered to the AVRISP mkII, and all
the possible responses that each command can give back to the host.
For all commands, the AVRISP mkII will return an answer with an answer ID that is
equal to the command ID. The first byte in a command is always the command ID, the
first byte in an answer is always the answer ID.
3.1 General Commands
3.1.1 CMD_SIGN_ON
This command returns a unique signature string for the AVRISP mkII with this
implementation of the protocol.
Table 3-1.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_SIGN_ON
Command id
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Table 3-2.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_SIGN_ON
Answer id
Status
1 byte
STATUS_CMD_OK
This command will always
return STATUS_CMD_OK
Signature length
1 byte
10
Length of signature string
10 bytes
"AVRISP_MK2"
The signature string (not null
terminated)
3.1.2 CMD_SET_PARAMETER
The host can set a multitude of parameters in the AVRISP mkII. See the 3.4:
Parameters for a description of each parameter. All parameters are one-byte values.
Table 3-3.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_SET_PARAMETER
Command id
Parameter ID
1 byte
Value
1 byte
Table 3-4.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_SET_PARAMETER
Answer id
Status
1 byte
STATUS_CMD_OK or
STATUS_CMD_FAILED
A status value indicating the
result of the operation
3.1.3 CMD_GET_PARAMETER
The host can also read different parameters from the AVRISP mkII.
Table 3-5.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_GET_PARAMETER
Command id
Parameter ID
1 byte
Which parameter to get
Table 3-6.
Answer format if command succeeds
Field
Size
Value
Description
Answer ID
1 byte
CMD_GET_PARAMETER
Answer id
Status
1 byte
STATUS_CMD_OK
A status value indicating
success
Signature length
1 byte
The parameter value
Table 3-7.
Answer format if fails
Field
Size
Value
Description
Answer ID
1 byte
CMD_GET_PARAMETER
Answer id
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Field
Size
Value
Description
Status
1 byte
STATUS_CMD_FAILED
A status value indicating that
the operation failed.
The only reason for the operation to fail is that an illegal parameter is requested.
3.1.4 CMD_OSCCAL
This command performs a calibration sequence as described in application note
AVR053.
Table 3-8.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_OSCCAL
Command id
Table 3-9.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_OSCCAL
Answer id
Status
1 byte
STATUS_CMD_OK or
STATUS_CMD_FAILED
A status value indicating the
result of the operation
3.1.5 CMD_LOAD_ADDRESS
This command will load an address into the AVRISP mkII. The next Program Flash,
Read Flash, Program EEPROM or Read EEPROM command will operate from the
address set with this command. The command is used in all programming modes. All
the abovementioned commands will increment an internal address counter, so this
command needs only to be sent once.
Table 3-10.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_LOAD_ADDRESS
Command id
Address
4 bytes
The address, four bytes, MSB
first
For word-addressed memories (program flash), the Address parameter is the word
address.
If bit 31 is set, this indicates that the following read/write operation will be performed
on a memory that is larger than 64KBytes. This is an indication to AVRISP mkII that a
load extended address
must be executed. See datasheet for devices with memories
larger than 64KBytes.
Table 3-11.
Answer format
.
Field
Size
Value
Description
Answer ID
1 byte
CMD_LOAD_ADDRESS
Answer id
Status
1 byte
STATUS_CMD_OK
This command will always
return STATUS_CMD_OK
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3.1.6 CMD_FIRMWARE_UPGRADE
When the host is trying to connect to the programmer, it checks the firmware version.
A firmware upgrade is initiated if a newer version is available on the PC.
The AVRISP mkII can "reboot" into upgrade mode by using this command.
Table 3-12.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_FIRMWARE_UPGRADE
Command id
Parameter ID
9 bytes
"fwupgrade"
String to enable upgrade
mode (not null terminated)
Table 3-13.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_FIRMWARE_UPGRADE
Answer id
Status
1 byte
STATUS_CMD_OK or
STATUS_CMD_FAILED
A status value indicating
the result of the operation
If the status returned is STATUS_CMD_OK, the AVRISP mkII will disconnect and
enter upgrade mode.
3.1.7 CMD_RESET_PROTECTION
This command resets the short circuit protection system after a short circuit state has
been returned by the PARAM_STATUS_TGT_CONN.
Table 3-14.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_RESET_PROTECTION
Command id
Table 3-15.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_RESET_PROTECTION
Answer id
Status
1 byte
STATUS_CMD_OK
This command will always
return STATUS_CMD_OK
3.2 ISP Programming Commands
These commands handles FLASH, EEPROM, fuse bytes, lock bits, signature and
oscillator calibration programming in ISP mode.
3.2.1 CMD_ENTER_PROGMODE_ISP
This command will make the target device enter programming mode.
XML path:
/AVRPART/ICE_SETTINGS/STK500_2/IspEnterProgMode/
Table 3-16.
Command form
Field
Size
Value
Description
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Field
Size
Value
Description
Command ID
1 byte
CMD_ENTER_PROG
MODE_ISP
Command id
timeout
1 byte
XML: timeout
Command time-out (in ms)
stabDelay
1 byte
XML: stabDelay
Delay (in ms) used for pin
stabilization
cmdexeDelay
1 byte
XML: cmdexeDelay
Delay (in ms) in connection with the
EnterProgMode command execution
synchLoops
1 byte
XML: synchLoops
Number of synchronization loops
byteDelay
1 byte
XML: byteDelay
Delay (in ms) between each byte in
the EnterProgMode command.
pollValue
(1)
1 byte
XML: pollValue
Poll value:
0x53 for AVR, 0x69 for AT89xx
pollIndex
1 byte
XML: pollIndex
Start address, received byte:
0 = no polling, 3 = AVR, 4 = AT89xx
cmd1
1 byte
Command Byte # 1 to be transmitted
cmd2
1 byte
Command Byte # 2 to be transmitted
cmd3
1 byte
Command Byte # 3 to be transmitted
cmd4
1 byte
Command Byte # 4 to be transmitted
Note:
1. The pollValue parameter indicates after which of the transmitted bytes on the SPI
interface to store the return byte, as the SPI interface is implemented as a ring
buffer (one byte out, one byte in)
Table 3-17.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_ENTER_PROG_M
ODE_ISP
Answer id
Status
1 byte
STATUS_CMD_TOUT,
STATUS_CMD_OK or
STATUS_CMD_FAILED
A status value indicating the result
of the operation
3.2.2 CMD_LEAVE_PROGMODE_ISP
This command will make AVRISP mkII leave programming mode. The device will be
put into normal operating mode.
XML path: /AVRPART/ICE_SETTINGS/AVRISP mkII_2/IspLeaveProgMode/
Table 3-18.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_LEAVE_PROGMODE_ISP
Command id
preDelay
1 byte
XML: preDelay
Pre-delay (in ms)
postDelay
1 byte
XML: postDelay
Post-delay (in ms)
Table 3-19.
Answer format
Field
Size
Value
Description
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Field
Size
Value
Description
Answer ID
1 byte
CMD_LEAVE_PROGMODE_ISP
Answer id
Status
1 byte
STATUS_CMD_OK
This command will always
return STATUS_CMD_OK
3.2.3 CMD_CHIP_ERASE_ISP
This command will perform a chip erase on the target device.
XML path: /AVRPART/ICE_SETTINGS/STK500_2/IspChipErase/
Table 3-20.
Command form
Field
Size
Value
Description
Command ID
1 byte
CMD_CHIP_ERASE_ISP
Command id
eraseDelay
1 byte
XML: eraseDelay
Delay (in ms) to ensure that the
erase of the device is finished
pollMethod
1 byte
XML: pollMethod
Poll method, 0 = use delay1=
use RDY/BSY command
cmd1
1 byte
Chip erase command byte #1
cmd2
1 byte
Chip erase command byte #2
cmd3
1 byte
Chip erase command byte #3
cmd4
1 byte
Chip erase command byte #4
Table 3-21.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_CHIP_ERASE_ISP
Answer id
Status
1 byte
STATUS_CMD_OK or
STATUS_CMD_TOUT
A status value indicating the
result of the operation
3.2.4 CMD_PROGRAM_FLASH_ISP
This command will program data into the FLASH memory of the target device if it
succeeds.
XML path:
/AVRPART/ICE_SETTINGS/STK500_2/IspProgramFlash/
Table 3-22.
Command form
Field
Size
Value
Description
Command ID
1 byte
CMD_PROGRAM_FLASH
_ISP
Command id
NumBytes
2 byte
Total number of bytes to
program, MSB first
mode
1 byte
XML: mode *
Mode byte*
delay
1 byte
XML: delay
Delay, used for different types
of programming termination,
according to mode byte
cmd1
1 byte
Command 1 (Load Page, Write
Program Memory)
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Field
Size
Value
Description
cmd2
1 byte
Command 2 (Write Program
Memory Page)
cmd3
1 byte
Command 3 (Read Program
Memory)
poll1
1 byte
XML: pollVal1
Poll Value #1
poll2
1 byte
XML: pollVal2
Poll Value #2 (not used for flash
programming)
Data
N bytes
N data
*Mode byte
The
mode
parameter is essential for how this command works. The bits in the mode
byte have the following meanings:
Bit #
Description
Mode
0
Word/Page Mode (0 = word, 1 = page)
1
Timed delay
2
Value polling
3
RDY/BSY polling
Word Mode
4
Timed delay
5
Value polling
6
RDY/BSY polling
7
Write page
Page Mode
The
Word/Page Mode
bit selects if the device supports page programming or not.
The command bytes are different for word and page mode. In word mode, the ISP
commands
Write Program Memory
and
Read Program Memory
are used. In page
mode,
Load Page
,
Write Program Memory Page
and
Read Program Memory
are
used. The read instruction is used if
Value Polling
is specified in the mode bit. The
Low/High byte selection bit (3
rd
bit in the Load Page, Write Program Memory
commands) is handled by AVRISP mkII, so leave this bit cleared.
According to the mode, different termination methods are selected –
Timed delay
,
Value polling
or
RDY/BSY polling
.
For paged operation, the
Write page
bit decides if
a Write Program Memory Page
command should be issued after the data has been loaded into the page buffer. For
devices with page size bigger than what can be transferred to AVRISP mkII in one
command, several CMD_PROGRAM_FLASH_ISP commands must be issued. In
such a case, only the last command should have the Write Page mode bit set.
NOTE: Only bit 0-6 are set in the XML file, because bit 7 is not constant and must be controlled
by the PC software.
When
value polling
is used to determine when a programming operation is complete,
poll1
must be supplied. This value indicates which value will be read from the device
until the programmed value is read. This indicates end of programming.
poll2
is
used
only for EEPROM programming.
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Table 3-23.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_PROGRAM_FLASH_ISP
Answer id
Status
1 byte
STATUS_CMD_OK,
STATUS_CMD_TOUT or
STATUS_RDY_BSY_TOUT
A status value indicating the
result of the operation
3.2.5 CMD_READ_FLASH_ISP
This command will read data from the FLASH memory of the target device if it
succeeds.
XML path:
/AVRPART/ICE_SETTINGS/ STK500_2/IspReadFlash/
Table 3-24.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_READ_FLASH_ISP
Command id
NumBytes
2 bytes
XML: blockSize
Total number of bytes to read,
MSB first
cmd1
1 byte
Read Program Memory
command byte #1. Low/High
byte selection bit (3rd bit) is
handled in the FIRMWARE.
Table 3-25.
Answer format if the command is executed
Field
Size
Value
Description
ANSWER ID
1 byte
CMD_READ_FLASH_ISP
Answer id
STATUS1
1 byte
STATUS_CMD_OK
Indicates success. Will always
read OK
DATA
N bytes
The data read from the device
STATUS2
1 byte
STATUS_CMD_OK
A status value indicating the
result of the operation. Will
always read OK
Table 3-26.
Answer format if the command was not executed
Field
Size
Value
Description
ANSWER ID
1 byte
CMD_READ_FLASH_ISP
Answer id
STATUS
1 byte
STATUS_CMD_FAILED
Indicates failure
3.2.6 CMD_PROGRAM_EEPROM_ISP
See the CMD_PROGRAM_FLASH_ISP command.
3.2.7 CMD_READ_EEPROM_ISP
See the CMD_READ_FLASH_ISP command.
3.2.8 CMD_PROGRAM_FUSE_ISP
This command programs the fuses of the target device.
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Table 3-27.
Command form
Field
Size
Value
Description
Command ID
1 byte
CMD_PROGRAM_FUSE_ISP
Command id
cmd1
1 byte
Command Byte #1
cmd2
1 byte
Command Byte #2
cmd3
1 byte
Command Byte #3
cmd4
1 byte
Command Byte #4
Note:
cmd1, cmd2, cmd3 and cmd4 are the four bytes of the low-level program fuse ISP
command.
Table 3-28.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_PROGRAM_FUSE_ISP
Answer id
Status1
1 byte
STATUS_CMD_OK
Will always read OK
Status2
1 byte
STATUS_CMD_OK
Will always read OK
3.2.9 CMD_READ_FUSE_ISP
This command reads the fuses of the target device.
Table 3-29.
Command form
Field
Size
Value
Description
Command ID
1 byte
CMD_READ_FUSE_ISP
Command id
RetAddr
1 byte
XML: pollIndex
Return address
cmd1
1 byte
Command Byte #1
cmd2
1 byte
Command Byte #2
cmd3
1 byte
Command Byte #3
cmd4
1 byte
Command Byte #4
Note:
RetAddr indicates after which of the transmitted bytes on the SPI interface to store
the return byte, as the SPI interface is implemented as a ring buffer (one byte out,
one byte in)
Table 3-30.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_READ_FUSE_ISP
Answer id
Status1
1 byte
STATUS_CMD_OK
A status value indicating the
result of the operation, always
OK
data
1 byte
The fuse byte read from the
device
Status2
1 byte
STATUS_CMD_OK
A status value indicating the
result of the operation, always
OK
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3.2.10 CMD_PROGRAM_LOCK_ISP
See CMD_PROGRAM_FUSE. This command is basically the same as the program
fuse command, only that ISP commands for programming the lock byte must be
supplied.
3.2.11 CMD_READ_LOCK_ISP
See CMD_READ_FUSE. This command is basically the same as the read fuse
command, only that ISP commands for reading the lock byte must be supplied.
3.2.12 CMD_READ_SIGNATURE_ISP
See CMD_READ_FUSE. This command is basically the same as the read fuse
command, only that ISP commands for reading one of the signature bytes must be
supplied.
3.2.13 CMD_READ_OSCCAL_ISP
See CMD_READ_FUSE. This command is basically the same as the read fuse
command, only that ISP commands for reading the OSCCAL byte must be supplied.
3.2.14 CMD_SPI_MULTI
This is a generic command that can be used to execute any of the ISP commands.
The command writes a number of bytes to the SPI bus, and returns a number of
bytes.
Table 3-31.
Command format
Field
Size
Value
Description
Command ID
1 byte
CMD_SPI_MULTI
Command ID
NumTx
1 byte
0-255
Number of bytes to transmit
NumRx
1 byte
0-255
Number of bytes to receive
RxStartAddr
1 byte
Start address of returned data.
Specifies on what transmitted byte
the response is to be stored and
returned.
TxData
0-255
bytes
The data
be transmitted. The size
is specified by NumTx
Note:
If the number of bytes to receive is greater than number of bytes to transmit, then the
firmware will pad with the necessary 0x00 bytes. This is in order to save time-
consuming transfer from PC to the programmer.
Table 3-32.
Answer format
Field
Size
Value
Description
Answer ID
1 byte
CMD_SPI_MULTI
Answer id
Status1
1 byte
STATUS_CMD_OK
Will always read OK
data
0-255
bytes
The data read from the ISP bus as
indicated in the command
Status2
1 byte
STATUS_CMD_OK
Will always read OK
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3.3 Return Values
This section describes all possible return values and their meaning in detail.
3.3.1 Success
Table 3-33.
Success
Value
Meaning
STATUS_CMD_OK
Command executed OK
3.3.2 Warnings
All warnings have MSB set to 1 and MSB-1 set to 0.
Table 3-34.
Success
Value
Meaning
STATUS_CMD_TOUT
Command timed out
STATUS_RDY_BSY_TOUT
Sampling of the RDY/nBSY pin timed out
STATUS_SET_PARAM_MISSING
The 'Set Device Parameters' have not been
executed in advance of this command
3.3.3 Errors
All errors have MSB and MSB-1 set to 1.
Table 3-35.
Success
Value
Meaning
STATUS_CMD_FAILED
Command failed
STATUS_CMD_UNKNOWN
Unknown command
3.4 Parameters
The following parameters can be read and/or written by the CMD_GET_PARAM and
CMD_SET_PARAM commands.
Table 3-36.
Success
Value
Meaning
R/W
PARAM_BUILD_NUMBER_LOW
Firmware build number, high byte
R
PARAM_BUILD_NUMBER_HIGH
Firmware build number, low byte
R
PARAM_HW_VER
Hardware version
R
PARAM_SW_MAJOR
Firmware version number, major byte
R
PARAM_SW_MINOR
Firmware version number, minor byte
R
PARAM_VTARGET
Target Voltage
R
PARAM_SCK_DURATION
ISP SCK duration
R/W
PARAM_RESET_POLARITY
Active low or active high RESET handling
W
PARAM_STATUS_TGT_CONN
Status of target connection
R
PARAM_DISCHARGEDELAY
Delay with higher resistance of reset line
W
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3.4.1 PARAM_BUILD_NUMBER_LOW
The PARAM_BUILD_NUMBER_LOW and PARAM_BUILD_NUMBER_HIGH together
return a number that is incremented for each build of the firmware. This number is
mainly for ATMEL internal use.
3.4.2 PARAM_BUILD_NUMBER_HIGH
See PARAM_BUILD_NUMBER_LOW.
3.4.3 PARAM_HW_VER
Returns a hardware revision number.
3.4.4 PARAM_SW_MAJOR
The PARAM_SW_MAJOR and PARAM_SW_MINOR returns the firmware version.
3.4.5 PARAM_SW_MINOR
See PARAM_SW_MAJOR.
3.4.6 PARAM_VTARGET
The parameter value is voltage in volts x10, i.e. a parameter value of 42 (decimal)
corresponds to 4.2V.
3.4.7 PARAM_SCK_DURATION
When using the ISP programming interface, the ISP clock frequency must not exceed
what the target device supports. (The maximum ISP clock frequency depends on the
device system clock, internal clock division etc.)
The AVRISP mkII supports ISP frequencies from 51 Hz up to 8.0 MHz. The value for
PARAM_SCK_DURATION can be found using the algorithm shown in chapter 6.3.
3.4.8 PARAM_RESET_POLARITY
The AVRISP mkII can program both AT90 (AVR) family and AT89 (8051) family of
microcontrollers. They have different RESET pin polarity. The AVR has active low
reset, while the AT89 has active high.
This parameter sets the polarity of the reset signal. Set the parameter to 1 when
programming AVRs, and 0 when programming AT89 controllers.
NOTE: AVRISP mkII stores this parameter in EEPROM, so they are available the next time
power is applied to the programmers.
3.4.9 PARAM_STATUS_TGT_CONN
This parameter returns the status of the target connection. Each bit has a separate
status. See table below:
Table 3-37.
Success
Bit value
Status
0x00
STATUS_ISP_READY
0x01
STATUS_CONN_FAIL_MOSI
0x02
STATUS_CONN_FAIL_RST