AP20161 - XMC1000 - S-series device

AN_20161_PL30_0013
XMC1000 S-series device
XMC1000
About this document
Scope and purpose
The XMC1000 S-series device provides Intellectual Property (IP) protection for your application code. The
device has a boot mode which handles the download of the encrypted application code. In this document, we
give an overview of the IP protection scheme and the command set, we describe the flash programming flow of
the XMC1000 S-series device, and provide instructions for encryption and downloading the application code to
the S-series device using the Secure Download Manager tool provided by Infineon.
Intended audience
This document provides the encryption concept of XMC1000 S-series device, so a field application engineer
could explain the benefit of this feature to a potential customer. For the XMC1000 S-series programmer, this
document provides a detailed description of the protocol for downloading encrypted code to the XMC1000 Sseries device.
References
[1]
The User’s Manual can be downloaded from http://www.infineon.com/XMC
Application Note
www.infineon.com
Please read the Important Notice and Warnings at the end of this document
1.0
2016-04-22
XMC1000 S-series device
XMC1000
Table of contents
Table of contents
About this document ............................................................................................................................................. 1
Table of contents ................................................................................................................................................... 2
1
1.1
1.1.1
1.1.1.1
1.1.1.2
1.1.1.3
1.1.2
1.2
1.2.1
1.2.2
1.2.2.1
1.2.3
1.2.3.1
1.2.4
1.2.4.1
1.2.5
1.2.5.1
1.2.5.2
Secure Bootstrap Loader (SBSL) ........................................................................................................ 3
IP protection scheme .............................................................................................................................. 3
Fundamental building blocks ............................................................................................................ 3
XMC1000 S-series device ............................................................................................................... 3
Software encryption tool .............................................................................................................. 3
Download tool with SBSL support ............................................................................................... 4
IP protection flow ............................................................................................................................... 5
SBSL command set ................................................................................................................................. 6
General command status response................................................................................................... 7
Protocol-specific commands ............................................................................................................. 9
FLASH_CHIP_RESET...................................................................................................................... 9
Status and configuration ................................................................................................................. 10
FLASH_GET_SBSL_STATUS ........................................................................................................ 10
Key management ............................................................................................................................. 12
FLASH_CHANGE_KEY .................................................................................................................. 12
Flash download ................................................................................................................................ 13
FLASH_LOAD_DATA .................................................................................................................... 13
FLASH_LOAD_CHECK_SIGNATURE ............................................................................................ 14
2
2.1
2.1.1
2.1.2
2.1.3
2.1.4
2.1.4.1
2.1.4.2
2.2
2.3
2.4
2.5
Programming via secure BSL ........................................................................................................... 15
Detailed description of download flow ................................................................................................ 17
Programming pin ............................................................................................................................. 17
Baudrate negotiation ....................................................................................................................... 17
Standard baudrate mode ................................................................................................................ 18
Enhanced baudrate mode ............................................................................................................... 18
Analysis of PDIV value ................................................................................................................. 20
Calculation of STEP value ........................................................................................................... 21
Reading SBSL Id out of the XMC1000 chip ............................................................................................ 21
Download of new key ............................................................................................................................ 22
Download of application code and data .............................................................................................. 23
Lifecycle of XMC1000 S-series device.................................................................................................... 24
3
Use of Infineon’s Secure Download Manager ................................................................................... 26
4
4.1
4.2
4.3
4.3.1
Programming the BMI value in SBSL mode ...................................................................................... 30
Macro and variable settings .................................................................................................................. 30
XMC™ Lib peripheral configuration structure ...................................................................................... 31
Interrupt service routine function implementation ............................................................................ 32
Main function implementation ........................................................................................................ 32
5
Revision history................................................................................................................................ 33
Application Note
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XMC1000 S-series device
XMC1000
Secure Bootstrap Loader (SBSL)
1
Secure Bootstrap Loader (SBSL)
Secure Bootstrap Loader (SBSL) is a start-up mode available in the XMC1000 to support the secure transfer of
encrypted application software, including code and data, and programming that Intellectual Property (IP) into
the device Flash. The encryption is based on the Advanced Encryption Standard (AES) and a key size of 128 bits.
1.1
IP protection scheme
The IP protection scheme is a system level solution to prevent embedded software cloning. The principles
behind the protection scheme are:

IP is always transported in its encrypted form from the moment it leaves the provider’s premises, until it is
downloaded into the device.

Only authorized devices allow the correct download and the subsequent operation of the IP.
− For example, encrypted IP created for one XMC1000 S-series variant is not permitted to be downloaded
into another variant of the XMC1000 S-Series device.
1.1.1
Fundamental building blocks
The protection scheme is based on these components:

XMC1000 S-series device

Software encryption tool

Download tool with SBSL support
1.1.1.1
XMC1000 S-series device
The default start-up mode for the XMC1000 S-series devices in the device delivery state is the SBSL mode, and
each variant of the devices is assigned a unique 128-bit identifier - SBSL ID.
The SBSL ID is stored in the flash configuration sector during device personalization. It can be read as part of
the SBSL status information with a FLASH_GET_SBSL_STATUS command (see section 1.2.3.1).
For the application code to identify an XMC1000 S-series device, the Flash address 1000’0F1CH can be read. A
read value of C0DE’1705H indicates that the device is an S-series device.
1.1.1.2
Software encryption tool
A PC-based software encryption tool called Secure Download Manager (SDM) is provided to:
1. Generate an AES 128-bit IP Key, KIP.
2. Encrypt the IP with KIP.
KIP is generated from a smart card that is connected to the SDM through a PC/SC card reader. There is no limit
to the number of keys that can be generated from the smart card.
KIP is used to encrypt the IP, and also to enable the download of IP into the device.
To encrypt the required IP, KIP and the SBSL ID of the target device are required as inputs. KIP can be created as
new, or selected from the list of previously generated keys.
The output of the encryption is a zipped file (<design>.zip for example) containing a further three files:

‘<design >.properties’ file;
Application Note
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XMC1000
Secure Bootstrap Loader (SBSL)
− carries the SBSL ID of the target device.

‘<design >_kc.ldf’ file;
− carries the encrypted KIP.

‘<design >_ip.ldf’ file;
− carries the encrypted IP.
1.1.1.3
Download tool with SBSL support
Functions
A download tool serves the following functions:

Acts as an interface to the target device.

Identifies the correct encrypted KIP and IP for the device based on its SBSL ID.

Downloads the encrypted KIP and IP into the device.

Handles any error response returned by the device.
Configuration
The SBSL uses the ASC (UART) protocol for communication between the host and the device, with the
configuration:

8 data bits.

1 stop bit.

No parity.

LSB first.

Channel selection based on which RxD pin the first Start and Header bytes are received.
Operation
Once the download tool has established the communication channel and baud rate, it uses the SBSL command
set to carry out the necessary actions on the device. The detailed download flow, including baud rate
negotiation, is described in section 2.1.
The SDM tool can also be used as a download tool. In this instance the user has to select the corresponding
zipped file generated during the IP encryption phase, to be downloaded into the device by SDM.
Application Note
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XMC1000
Secure Bootstrap Loader (SBSL)
1.1.2
IP protection flow
The IP protection flow consists of two main phases:

Encryption phase.

Download phase.
Encryption
The encryption phase is entered once the IP provider is provided with the SBSL ID of the target devices. During
this phase, the IP provider uses the software encryption tool to encrypt the IP with an IP key. The output is a
zipped file containing the encrypted IP and associated files.
Download
The download phase is entered once the device programmer receives the zipped file generated from the
encryption phase. During the download phase, the device programmer uses the download tool to install the IP
key in the device flash configuration sector, before downloading the encrypted IP. The encrypted IP will be
decrypted by the SBSL, using the installed IP key, and programmed into the device flash memory.
Note: The SBSL ID of the target device must match with the one used during the encryption phase, otherwise the
download tool will flag an error and data download to the unknown device will fail.
Once the IP is successfully programmed into the device flash memory, the SBSL switches the Boot Mode Index
(BMI) to the User Productive (UP) mode and begins execution of the IP.
Note: In user productive mode, all external accesses to the device are disabled. If it is intended to support future
updates of the IP, the IP must be able to call the Request BMI Installation user routine in the boot ROM to
switch the BMI back to SBSL mode. When reverting back to SBSL mode, the flash memory will be restored
to the delivery state and the download phase can be repeated with the new IP.
Application Note
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XMC1000
Secure Bootstrap Loader (SBSL)
1.2
SBSL command set
The SBSL protocol is as follows:
Figure 1
Data flowchart for the SBSL Loader protocol
When ‘Lx’ is not equal to zero, the SBSL device will returns the received ‘INS’ byte as ‘header acknowledge’. For
example for FLASH_CHIP_RESET command (chapter 1.2.2.1), the Lc is 0x00, so there is no ‘header acknowledge’
from the SBSL device.
If the SBSL requires more time, it sends one or more 'Waiting Time Extension Requests' as illustrated by Figure
2 for the SBSL loader command ' FLASH_LOAD_CHECK_SIGNATURE ' ('A0 21 00 00 00').
Application Note
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XMC1000
Secure Bootstrap Loader (SBSL)
Figure 2
Data flowchart for waiting time extension request
About SBSL commands
An SBSL command is identified by two 8-bit integers representing the command class CLA and command
instruction INS. It also contains:

Two 8-bit command parameters P1 and P2.

An 8-bit field Lc, indicating the number of bytes of the following command data.

Nc bytes of command data.

An 8-bit field Le, indicating the maximum number of response bytes expected.
SBSL commands are designed to transport payload data only in one direction; i.e. to the SBSL in the
command’s data field, or from the SBSL in the response’s data field, but not in both at the same time.
SBSL commands
Table 1
CLA
INS
0xA0
0x00 FLASH_CHIP_RESET
Triggers chip reset
0xA0
0x10 FLASH_GET_SBSL_STATUS
Retrieves the 39-byte SBSL status information,
rSbslStatus
0xA0
0x12 FLASH_CHANGE_KEY
Updates the IP Key, KIP and its label, LIP
0xA0
0x20 FLASH_LOAD_DATA
Loads data to flash memory
0xA0
0x21 FLASH_LOAD_CHECK_SIGNATURE
Verifies checksum of downloaded data
1.2.1
Name
Description
General command status response
The SBSL always returns a two-byte status word, SW1 and SW2, and data (if applicable) in response to a SBSL
command.
Table 2 lists the general command status response values. Any additional command-specific responses are
listed in the respective command description.
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XMC1000
Secure Bootstrap Loader (SBSL)
Command status response values SW1-SW2
Table 2
SW1
SW2
0x90
0x00 Success
Normal
0x64
0x00 Execution error: NVM unchanged
Execution error
0x65
0x00 Execution error: NVM changed
0x65
0x81 NVM is changed; memory failure
0x67
0x00 Wrong length (Lc or Le)
0x69
0x82 Insufficient security state
0x69
0x83 Authentication method blocked
0x69
0x84 Reference data not usable
0x69
0x85 Conditions of use not fulfilled
0x6A
0x00 Wrong parameters P1 and P2
0x6A
0x86 Wrong parameters P1 and P2
0x6C
L’e
0x6D
0x00 Invalid instruction byte (INS)
0x6E
0x00 Invalid class byte (CLA)
Application Note
Meaning
Processing status
Checking error
Wrong length Le, SW2 indicates the
expected length L’e
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XMC1000
Secure Bootstrap Loader (SBSL)
1.2.2
Protocol-specific commands
1.2.2.1
FLASH_CHIP_RESET
This command triggers a chip reset. The response is returned and the chip reset takes place.
Security
None
Parameters
None
Syntax
Table 3
FLASH_CHIP_RESET syntax
CLA
INS
P1
P2
Lc
Data field
Le
0xA0
0x00
0x00
0x00
0x00
-
-
Response
Table 4
FLASH_CHIP_RESET response
Data field
SW1
SW2
Status
-
0x90 0x00 Success
Return value
The command always reports success.
Application Note
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XMC1000 S-series device
XMC1000
Secure Bootstrap Loader (SBSL)
1.2.3
Status and configuration
1.2.3.1
FLASH_GET_SBSL_STATUS
This command retrieves the 39-byte SBSL status information, rSbslStatus, from the chip. rSbslStatus is useful to
determine further steps for handling the SBSL or for comparison to the expected state during personalization.
During SBSL status preparation, the SBSL executes the erase flash procedure, if the SBSL has been previously
re-activated and the user flash area is therefore scheduled for erasure. Waiting Time Extension (WTX) requests
are sent during the flash erase to obey protocol timing. A byte of value 0x60 is sent for each WTX request.
Security
None.
Parameters
None.
Syntax
FLASH_GET_SBSL_STATUS syntax
Table 5
CLA
INS
P1
P2
Lc
Data Field
Le
0xA0
0x10
0x00
0x00
-
-
0x27
Response
FLASH_GET_SBSL_STATUS response
Table 6
Data field
rSbslStatus
SW1
SW2
Status
rSbslStatus
0x65 0x81 Erase procedure failure
-
0x67 0x00 Wrong Le
0x90 0x00 Success
Return value
This command returns rSbslStatus.
rSbslStatus structure
Table 7
Offset Bytes Value
Description
0
4
“SBSL”
Magic name identifying structure
4
1
0xC0
SBSL version tag
5
1
0x04
Length of following data
6
1
0x06
XMC1000
7
3
vr rb bb
Software version (v), revision (r), build (b)
10
1
0xC1
SBSL patch version tag
11
1
0x03
Length of following data
12
3
vr rb bb
Patch version (v), revision (r), build (b)
15
1
0xC2
SBSL state tag
Application Note
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XMC1000
Secure Bootstrap Loader (SBSL)
Offset Bytes Value
Description
16
1
0x04
Length of following data
17
1
ULC
SBSL unified life cycle
18
1
V
V.0 bit: 0 -> SBSL is not valid; 1 -> SBSL is valid
V.1 bit: 0 -> KIP is not valid or set; 1 -> KIP is valid
Others: reserved
19
1
0x00
Reserved
20
1
FDTC
21
1
0xC3
Flash download trial counter
Indicates the current remaining number of download attempts.
Every start of a download sequence decreases the value of FDTC by one, upon
receiving the first ‘FLASH_LOAD_DATA’ command.
If the download ended successfully (verified by a checksum calculation, see
section 2.4), FDTC is reset to its initial start value.
If the download failed, FDTC remains on its decreased value.
In case FDTC has reached 0, further flash downloads are irreversibly blocked
and the affected chip needs to be replaced with a new one.
SBSL ID tag
22
1
0x10
Length of following data
23
16
SBSL ID
SBSL ID
Application Note
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XMC1000
Secure Bootstrap Loader (SBSL)
1.2.4
Key management
1.2.4.1
FLASH_CHANGE_KEY
This command updates the IP Key KIP, and its label LIP, in the chip with the ones contained in the 20-byte key
field.
Security
None
Parameters
None
Syntax
Table 8
FLASH_CHANGE_KEY syntax
CLA
INS
P1
P2
Lc
Data field
Le
0xA0
0x12
0x01
0x00
0x14
20-byte key
field
-
Response
Table 9
FLASH_CHANGE_KEY response
Data Field
SW1
SW2
Status
-
0x90
0x00
Success
-
0x67
0x00
Wrong Lc
-
0x69
0x82
Insufficient security state
-
0x69
0x84
Mismatch between key and key label
-
0x6A
0x86
Wrong parameters P1 and P2
Return value
This command either returns success (0x90 0x00) or an error condition as shown in Table 9.
Application Note
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XMC1000 S-series device
XMC1000
Secure Bootstrap Loader (SBSL)
1.2.5
Flash download
1.2.5.1
FLASH_LOAD_DATA
This command delivers a configurable length of encrypted SBSL download data to the chip. This data is handed
over to the decryption module of the SBSL.
After decryption, the data is decoded and complete pages are flashed into the Flash memory. A checksum is
computed over all data blocks and validated with the FLASH_LOAD_CHECK_SIGNATURE command.
Note: The flash download sequence must be explicitly finished with a following FLASH_LOAD_CHECK_SIGNATURE
command.
Security
The IP key KIP has to be in place.
Parameters
Dl is the encrypted SBSL data of l bytes.
Syntax
Table 10
FLASH_LOAD_DATA syntax
CLA
INS
P1
P2
Lc
Data field
Le
0xA0
0x20
0x00
0x00
l
Dl
-
Response
Table 11
FLASH_LOAD_DATA response
Data field
SW1
SW2
Status
-
0x90 0x00 Success
-
0x64 0x00 Fatal
No fab-out state or KIP is not set.
-
0x65 0x00 Error updating the SBSL state; for example FDTC.
-
0x65 0x01 Fatal
Write to flash outside user flash range was suppressed, chip enters sleep
mode.
-
0x65 0x81 Fatal
NVM programming error occurred, chip enters sleep mode.
-
0x69 0x82 Insufficient security state. No download trials are left for example, or KIP is
missing.
-
0x69 0x84 Error in download stream was found.
-
0x69 0x85 Error interpreting a download record.
Return value
The command either returns success or an error status value.
Application Note
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XMC1000
Secure Bootstrap Loader (SBSL)
In case the “no fab-out” state (0x64 0x00) is returned, the following causes may apply:

The chip is not in a fab-out state anymore; i.e. data has already been flashed into the Flash memory using
the SBSL. After re-activation of the SBSL, the FLASH_GET_SBSL_STATUS command described in section
1.2.3.1 must be run to erase the user flash.

KIP, the IP key, is not set. It must be set by using the command FLASH_CHANGE_KEY described in section
1.2.4.1.
In case of a fatal error during execution, the SBSL restarts the chip immediately after sending the command
response.
1.2.5.2
FLASH_LOAD_CHECK_SIGNATURE
This command verifies the checksum computed over all data blocks and finishes the flash download
procedure.
The actual download signature verification is performed within the download stream interpretation. Its result is
kept in memory until it is retrieved with this command.
Immediately after reporting the status the Secure Boot Strap Loader activates the downloaded user flash
software in the case of success, or otherwise restarts the chip.
Security
The IP key KIP has to be in place.
Parameters
None.
Syntax
Table 12
FLASH_LOAD_DATA syntax
CLA
INS
P1
P2
Lc
Data field
Le
0xA0
0x21
0x00
0x00
0x00
-
-
Response
Table 13
FLASH_LOAD_DATA response
Data field
SW1
SW2
Status
-
0x90 0x00 Success
-
0x65 0x00 Wrong hash value
-
0x65 0x81 Flash programming error
-
0x69 0x82 No download started
Return value
The command either returns success or an error status value.
Application Note
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XMC1000
Programming via secure BSL
2
Programming via secure BSL
The download of application software and data to an XMC1000 device can be performed via Infineon’s secure
download manager as well as via a proprietary download tool (developed by an OEM for example).
Figure 3
Components required for download of application software to XMC1000
Both tools use the same ‘<design>.zip’ file as input. The download input file (*.zip) shall be generated with
Infineon’s Secure Download Manager tool.
Note: Please refer to section 1.1.1.2 for the functionality of the three files to be found in <design>.zip.
Figure 4 illustrates the operations executed during a download:
1. A baudrate for communication between the XMC1000 chip and the download tool has to be negotiated.
2. The SBSL Id’s stored on-chip and used as the base for key generation and encryption of the download
information have to be compared. In case of a miss-match, the download operation has to be aborted,
because the decryption of the downloaded key and software would fail.
3. The SBSL Id specific key has to be downloaded.
4. The SBSL Id specific code and data have to be downloaded.
Application Note
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XMC1000
Programming via secure BSL
Power-On
(effects ‘HW Reset’)
1
negotiate baud rate
Read SBSL ID from file
<design>.properties
2
Read SBSL ID from
XMC1000 chip
no
Do both SBSL IDs match
Abort operation
yes
3
Download content of file
<design>_kc.ldg
4
Download content of file
<design>_ip.ldg
end
Figure 4
Simplified download flow
Application Note
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XMC1000
Programming via secure BSL
2.1
Detailed description of download flow
The following sections explain the download flow.
2.1.1
Programming pin
Two sets of pins/channels are available to choose for programming the XMC1000 S-series device. Both channel
0 and 1 are ready for UART communication after power up.
XMC1000
S-series
Channel 0 P0.14
P0.15
Channel 1
P1.3
P1.2
RXD
TXD
RXD
TXD
ASC_BSL
(Full duplex)
Figure 5
Pins used for UART communication with XMC1000 S-series device during programming
2.1.2
Baudrate negotiation
XMC1000 devices are equipped with baudrate recognition logic working in the range between 300 and 115,200
Baud, depending on the internal MCLK (see Table 14).
After a reset, XMC1000 devices can operate in different baudrate modes:

Standard baudrate mode
− In this mode the XMC1000 always operates with a fixed baudrate that is determined by the first bytes
arriving on UART’s Rx line.

Enhanced baudrate mode
− In this mode the XMC1000 starts with an initial baudrate that is also set by the first bytes arriving on
UART’s Rx line.
− XMC1000’s initial baudrate can be modified by the download tool to a ‘working baudrate’ up to 3,996,000
Baud depending on the internal MCLK (see Table 14).
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XMC1000
Programming via secure BSL
2.1.3
Standard baudrate mode
The “Standard baudrate mode” is activated by the download tool on the ‘0x00 0x6C’ command. In response,
the XMC1000 answers with ‘0x5D’. If a different reply is returned, the XMC1000 fails to recognize the baudrate
used by the download tool.
Figure 6
Protocol flow in standard baudrate mode
2.1.4
Enhanced baudrate mode
The Enhanced Baudrate mode is activated by the download tool via the ‘0x00 0x93’ command.
XMC1000 answers with ‘0xA2’ and a ‘PDIV’ value in the same baudrate.
The download tool analyses the received ‘PDIV’ value and uses it for the calculation of the ‘STEP’ value defining
the requested ‘final baudrate’.
After transmission of ‘0xF0’ by both XMC1000 and the download tool, the switch to the ‘final baudrate’ has been
successfully finished.
AA step devices
Note: For AA step devices, the ‘0xF0’ Acknowledge from an XMC1xxx device is transmit in the ‘final baudrate’ as
shown in Figure 7.
AB step devices
Note: For AB step devices, the ‘0xF0’ Acknowledge from an XMC1xxx device is transmit in the ‘initial baudrate’ as
shown in Figure 8.
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XMC1000 S-series device
XMC1000
Programming via secure BSL
Figure 7
Protocol flow in enhanced baudrate mode for AA step devices
Application Note
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XMC1000 S-series device
XMC1000
Programming via secure BSL
Infineon’s Secure
Download Manager
or
OEM’s Proprietary
Download Tool
XMC1xxx
Chip
0x00 0x93
select ‘Enhanced Baudrate Mode’
0xA2 <MSB of ‘PDIV’> <LSB of ‘PDIV’>
‘initial baudrate’ established, return PDIV
<LSB of ‘STEP’> <MSB of ‘STEP’>
Send ‘STEP’ value to change XMC1xxx’s baudrate
0xF0
Return ‘Acknowledge’ in ‘initial baudrate’
0xF0
Return ‘Acknowledge’ in ‘final baudrate’
Figure 8
Protocol flow in enhanced baudrate mode for AB step devices
2.1.4.1
Analysis of PDIV value
The returned PDIV value is used to calculate the Master Clock Frequency (MCLK) in the XMC1000 device
according to following formula:
MCLK = Initial baudrate x (PDIV + 1) x 8
Example

Initial baudrate = 9,600 Baud = 9,600 Hz

PDIV = 0x00 0x67 = 0x0067 = 103
Results in: MCLK = 9,600 Hz x 104 x 8 = 7.9872 MHz ~ 8 MHz.
As indicated by Table 14, there are different minimum and maximum baudrates that are allowed depending on
the current MCLK value.
Table 14
Supported baudrates
MCLK
Minimum initial baudrate
(Baud)
Maximum initial baudrate
(Baud)
Maximum final baudrate
(Baud)
2 MHz (min)
300
7200
249750
8 MHz
1200
28800
999000
16 MHz
2400
57600
1998000
32 MHz
4800
115200
3996000
Application Note
20
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2016-04-22
XMC1000 S-series device
XMC1000
Programming via secure BSL
2.1.4.2
Calculation of STEP value
The STEP value is used to adjust the final baudrate according to the formula:
STEP = 1024 x (Target Baudrate / Initial Baudrate) / (PDIV + 1)
Example

Initial Baudrate = 9,600 Baud

Target Baudrate = 115,200 Baud

PDIV = 0x00 0x67 = 0x0067 = 103
STEP = 1024 x (115,200 / 9,600) / 104 = 118.16 ~ 118 = 0x0076 = 0x00 0x76.
2.2
Reading SBSL Id out of the XMC1000 chip
The SBSL Id and further information are read via the flash Get SBSL Status command from the XMC1000 device.
Figure 9
Protocol flow for SBSL Id evaluation
Note: For the layout of the flash get SBSL status reply, please refer to Table 7.
Application Note
21
1.0
2016-04-22
XMC1000 S-series device
XMC1000
Programming via secure BSL
2.3
Download of new key
File <design>_kc.ldf contains the new key that has to be downloaded before the new application code. The file
contains:
# SBSLID: 5342534C2D4944203D20323232323232
# LIP: 96377500
A0 12 01 00 14 96 37 75 00 36 BC ED 8E 91 B4 F5 75 E6 86 FA CA B1 BB CA C4
Note: Lines starting with ‘#’ hold comments and must not be sent to a XMC1000 device.
The third line contains:

a command APDU (‘A0 12 01 00 14’) announcing 0x14 = 20 following key bytes.

the encrypted new key value.
When XMC1000 accepts the new key, it returns ‘90 00’. Otherwise, a 2 byte ‘error SW1 SW2‘ (for example ‘67 xx’)
is returned.
Figure 10
Protocol flow for download of new decryption key
Application Note
22
1.0
2016-04-22
XMC1000 S-series device
XMC1000
Programming via secure BSL
2.4
Download of application code and data
File <design>_ip.ldf contains the encrypted application code and data, which have to be downloaded to
XMC1000. The file layout is as follows:
# LIP: 96377500
A0 20 00 00 82 A0 00 00 00 16 ... 1E E3 D4 4E E6 68 CA 71 35 65
A0 20 00 00 82 A0 00 00 00 16 ... 2A A6 15 4C A5 5F DD 3E 40 9E
.
.
.
.
A0 20 00 00 22 A0 00 00 00 16 ... C5 DE
A0 21 00 00 00
Note: Lines starting with ‘#’ hold comments and must not be sent to a XMC1000 device.
The following lines contain:

a command APDU
− ‘A0 20 00 00 xx’ announcing ‘xx’ following code and/or data bytes.
− ‘A0 21 00 00 00’ initiating a checksum calculation over all downloaded bytes.

the affiliated code and/or data bytes
When the XMC1000 successfully processes the new APDU and <code and/or data bytes> string, it returns ‘90 00’.
Otherwise, a 2 byte ‘error SW1 SW2‘ (e.g. ‘67 xx’) is returned.
Application Note
23
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2016-04-22
XMC1000 S-series device
XMC1000
Programming via secure BSL
Figure 11
Protocol flow for download of new application code and data
2.5
Lifecycle of XMC1000 S-series device
State diagram of the XMC1000 S-series:
Application Note
24
1.0
2016-04-22
XMC1000 S-series device
XMC1000
Programming via secure BSL
Power_On Reset
SBSL Loader
activated, baudrate
undefined, key
exchange enabled,
download disabled
Init Communication
Standard Baudrate Mode or
Enhanced Baudrate Mode
Analize failure
and
fix errors
Final baudrate
adjusted, key
exchange enabled,
download disabled
Download
IP key
Failed
Passed
SBSL Loader will be
blocked after 16
successive failed
downloads, XMC1xSx
cannot be used
anymore.
Download
enabled
Download IP code and
data
Failed
Passed
SBSL Loader
deactivated,
downloaded IP
activated,
baudrate defined
by IP
Figure 12
State diagram of SBSL flow
Application Note
25
1.0
2016-04-22
XMC1000 S-series device
XMC1000
Use of Infineon’s Secure Download Manager
3
Use of Infineon’s Secure Download Manager
The download flow is automatically handled by Infineon’s secure download manager tool. The user only has to:

create a ‘Download project’, bearing in mind all of the required information for the download.

specify the path to the requested ‘<design>.zip’ file.

click the ‘Start Icon’.
These actions can be made interactively or can be executed via a <JavaScript>.js file that is called by a batch
process.
Note: For details of the <JavaScript>.js capabilities, see the online help in Infineon’s secure download manager
tool.
The download project wizard is started from File > New > Project :
Figure 13
Initial wizard window for creation of a download IP-project
In the next window the selection of the ‘Interactive - use XMC1xxx-chip with serial interface’ option is
recommended in order to read all information requested from the linked XMC1000 device. Alternatively, the
required information can be manually defined via the ‘offline’ option.
Application Note
26
1.0
2016-04-22
XMC1000 S-series device
XMC1000
Use of Infineon’s Secure Download Manager
Figure 14
Collection of chip properties for the ‘Download IP-Project’
For access to the target device, Infineon’s Secure Download Manager tool requires the operation parameters of
the ‘Chiploader’ that interfaces with the target XMC1000 device. This information is summarized in a *.cld file
that has been pre-defined by Infineon, or has been generated by the user themselves via the File > New >
Chiploader menu commands.
Figure 15
Query operation parameters of Chiploader
The path and name of the *.zip file containing the SBSL ID, the new decryption key, and the new application
code and data, is queried by the Select IP File window.
Application Note
27
1.0
2016-04-22
XMC1000 S-series device
XMC1000
Use of Infineon’s Secure Download Manager
Figure 16
Query path and name of <design>.zip file
All information and references required for a successful execution of the Download Project are stored in a *.ldc
file who’s path and name is queried by the Wizard - Save file window.
Figure 17
Select path and name of file storing download project properties
Finally, the download is started by a click on the ‘download icon’ indicated by the red colored arrow in the
following figure:
Application Note
28
1.0
2016-04-22
XMC1000 S-series device
XMC1000
Use of Infineon’s Secure Download Manager
Figure 18
Start of download
Application Note
29
1.0
2016-04-22
XMC1000 S-series device
XMC1000
Programming the BMI value in SBSL mode
4
Programming the BMI value in SBSL mode
Once the IP is successfully programmed into the device flash memory, the SBSL switches the Boot Mode Index
(BMI) to the User Productive (UP) mode and begins execution of the IP. Unless the application code of the
downloaded IP changes the BMI mode, there is no way to change the device BMI to ASC_SBSL mode.
If you need to change the IP and re-program the XMC1000 S-series device, you will need to embed code in the IP
application code to allow changing the Boot Mode Index (BMI) value to Secure BootStrap Loader Mode (i.e.
ASC_SBSL= 0xFFFA .) The user routine (XMC1000_BmiInstallationReq()) available inside the ROM allows
application software to call and change the BMI value.
In this example, an external interrupt is triggered based on a rising edge event detected on P2.0. In the
interrupt handler, the routine to install a new BMI to ASC_SBSL mode is called. The rising event is set up using
the Event Request Unit (ERU) which triggered an interrupt on ERU0.SR0.
XMC1000_BmiInstallationReq(0xFFFA);
ERU0
ETL
P2.0
B
Trigger
OGU
IOUT0
SR0
NVIC
(ERU0.SR0)
1. Initially, P2.0 is connected to GND.
2. To trigger a change in BMI to ASC_SBSL, P2.0 is connected to VCC.
3. This creates a rising edge on P2.0 and triggers an external interrupt event.
4. In the ISR, the routine for changing the BMI is called.
Figure 19
4.1
Changing the BMI from an external interrupt
Macro and variable settings
/* XMC™ Lib project includes: */
#include <xmc_eru.h>
#include <xmc_gpio.h>
#include <xmc_scu.h>
/* Project definitions */
#define ROM_FUNCTION_TABLE_START (0x00000100)
#define _BmiInstallationReq (ROM_FUNCTION_TABLE_START + 0x08)
/* Pointer to Request BMI installation routine */
#define XMC1000_BmiInstallationReq \
(*((unsigned long (**) (unsigned short)) _BmiInstallationReq))
Application Note
30
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2016-04-22
XMC1000 S-series device
XMC1000
Programming the BMI value in SBSL mode
4.2
XMC™ Lib peripheral configuration structure
/* XMC GPIO Configuration */
XMC_GPIO_CONFIG_t input_config =
{
.mode = XMC_GPIO_MODE_INPUT_TRISTATE,
.input_hysteresis = XMC_GPIO_INPUT_HYSTERESIS_STANDARD
};
/* Event Trigger Logic Configuration - ERU0.0B0 (P2_0) selected */
XMC_ERU_ETL_CONFIG_t ERU0_ETL_Config =
{
.input_a = (uint32_t)XMC_ERU_ETL_INPUT_A0, /* Event input selection for A(0-3) */
.input_b = (uint32_t)XMC_ERU_ETL_INPUT_B0, /* Event input selection for B(0-3) */
.enable_output_trigger = (uint32_t)1,
.status_flag_mode =
(XMC_ERU_ETL_STATUS_FLAG_MODE_t)XMC_ERU_ETL_STATUS_FLAG_MODE_HWCTRL,
/* Select the edge/s to convert as event */
.edge_detection = XMC_ERU_ETL_EDGE_DETECTION_RISING,
/* Select the source for event */
.output_trigger_channel = XMC_ERU_ETL_OUTPUT_TRIGGER_CHANNEL0,
.source = XMC_ERU_ETL_SOURCE_B
};
/* Output Gating Unit Configuration - Gated Trigger Output */
XMC_ERU_OGU_CONFIG_t ERU0_OGU_Config =
{
.peripheral_trigger = 0U, /* OGU input peripheral trigger */
.enable_pattern_detection = false, /* Enables generation of pattern match event */
/* Interrupt gating signal */
.service_request = XMC_ERU_OGU_SERVICE_REQUEST_ON_TRIGGER,
.pattern_detection_input = 0U
};
Application Note
31
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2016-04-22
XMC1000 S-series device
XMC1000
Programming the BMI value in SBSL mode
4.3
Interrupt service routine function implementation
/* Interrupt handler for external trigger interrupt */
//void IRQ3_Handler(void)
void ERU0_0_IRQHandler(void)
{
/* BMI_installation routine to set BMI = ASC_SBSL */
XMC1000_BmiInstallationReq(0xFFFA);
}
Note:
For XMC1400 series device, due to the interrupt handler “void ERU0_0_IRQHandler(void)” should be
replaced with “void IRQ3_Handler (void)”
4.3.1
Main function implementation
int main(void)
{
/* Sets up the ERU- ETL and OGU for the external trigger event */
XMC_ERU_ETL_Init(XMC_ERU0, 0, &ERU0_ETL_Config);
XMC_ERU_OGU_Init(XMC_ERU0, 0, &ERU0_OGU_Config);
/* Initializes the gpio input and output */
XMC_GPIO_Init(P2_0, &input_config);
/* Enable the interrupt – ERU0_SR0 */
//XMC_SCU_SetInterruptControl(3, XMC_SCU_IRQCTRL_ERU0_SR0_IRQ3); //Only for XMC140x
NVIC_EnableIRQ(3U);
/* Placeholder for user application code. */
while(1U)
{
}
}
Note:
For XMC1400 series device, uncomment the code line “XMC_SCU_SetInterruptControl(3,
XMC_SCU_IRQCTRL_ERU0_SR0_IRQ3);”
Application Note
32
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2016-04-22
XMC1000 S-series device
XMC1000
Revision history
5
Revision history
Major changes since the last revision
Page or reference
V1.0, 2016-2
Application Note
Description of change
Initial release
33
1.0
2016-04-22
Trademarks of Infineon Technologies AG
AURIX™, C166™, CanPAK™, CIPOS™, CoolGaN™, CoolMOS™, CoolSET™, CoolSiC™, CORECONTROL™, CROSSAVE™, DAVE™, DI-POL™, DrBlade™, EasyPIM™,
EconoBRIDGE™, EconoDUAL™, EconoPACK™, EconoPIM™, EiceDRIVER™, eupec™, FCOS™, HITFET™, HybridPACK™, Infineon™, ISOFACE™, IsoPACK™,
i-Wafer™, MIPAQ™, ModSTACK™, my-d™, NovalithIC™, OmniTune™, OPTIGA™, OptiMOS™, ORIGA™, POWERCODE™, PRIMARION™, PrimePACK™,
PrimeSTACK™, PROFET™, PRO-SIL™, RASIC™, REAL3™, ReverSave™, SatRIC™, SIEGET™, SIPMOS™, SmartLEWIS™, SOLID FLASH™, SPOC™, TEMPFET™,
thinQ!™, TRENCHSTOP™, TriCore™.
Trademarks updated August 2015
Other Trademarks
All referenced product or service names and trademarks are the property of their respective owners.
Edition 2016-04-22
Published by
Infineon Technologies AG
81726 Munich, Germany
©ifx1owners.
2016 Infineon Technologies AG.
All Rights Reserved.
Do you have a question about this
document?
Email: [email protected]
Document reference
AN_20161_PL30_0013
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