CN104281470B - A kind of Multiple MCU System method for upgrading software based on single external serial ports - Google Patents
A kind of Multiple MCU System method for upgrading software based on single external serial ports Download PDFInfo
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Abstract
The invention discloses a kind of Multiple MCU System method for upgrading software based on single external serial ports, the MCU of internal system is carried out interconnection by serial ports and constitutes many MCU interacted systems by this method, and the period for entering bootloader according to system by host computer judges and selected the chip for needing to update.Host computer selects the path that code data is transmitted by criterion of the minimum transfer time, sets up and is connected with slave computer, and slave computer performs the forwarding of data according to routing iinformation, so as to realize the renewal of any chip code in whole system.The designed protocol definition basic format of data transfer, and used the stability for automatically selecting and retransmitting and ensureing code update.This method only needs to single serial ports and can be achieved, and occupies few hardware resource, and the exploitation and development to such as autonomous underwater vehicle instrument system with seal request provide easy, reliable online upgrading scheme, with important application value.
Description
Technical field
The invention belongs to MCU system development technique field, and in particular to a kind of Multiple MCU System based on single external serial ports is soft
Part upgrade method.
Background technology
In recent years, with the progressively development of chip technology so that the data-handling capacity of chip, further improve, in profit
During being developed with various chips, product reliability, cost and the requirement that updates also further are carried therewith
It is high.
Relative to software, the update speed of hardware platform is slower, is inevitably present in the software of early development
The problem of some are difficult to realize, putting into practice, using and test process in these problems can gradually expose, it is necessary to constantly carry out
Amendment.Still meet under conditions of current application demand, directly realize on a hardware platform to software code in hardware platform
Renewal and upgrading, development cost can be saved, increased economic efficiency.
In actual applications, it is more ripe to the upgrading of single MCU chip, but in a system, often exist
Multigroup chip to cooperate, multiple MCU chip codes are updated still without ripe technical scheme, pass through reasonable land productivity
The autgmentability of system can be improved with the hardware resource of chip, increase the function of system, therefore how research is using limited hard
Part resource realizes the exploitation and great significance for design for whole system to the code update and upgrading of multigroup chip.
Due to the demand of some applications, some systems need to be operated under air-proof condition, such as autonomous underwater vehicle
(AUV), underwater communications system, compared with other kinds of system, this system it is expensive, more need a kind of code to exist
The method of line upgrading.Need to reduce external interface as far as possible for the code update and online upgrading of these systems, reduce whole
System package produces the risk of seepage, it is ensured that normal, the stability of increase system work of system context.
The content of the invention
For the above-mentioned technical problem present in prior art, the invention provides a kind of based on many of single external serial ports
MCU system method for upgrading software, realizes that simple, stability is good, for many MCU of Multiple MCU System especially in a sealed meter environment
The code update and online upgrading of system have important value.
A kind of Multiple MCU System method for upgrading software based on single external serial ports, comprises the following steps:
(1) each MCU in Multiple MCU System is numbered and each MCU is had unique No. ID;
(2) communication mode of the setting external serial ports of Multiple MCU System and carry out upper electricity, so host computer by external serial ports to
Main MCU in system is transmitted into the instruction of Bootloader programs, and then is directly or indirectly turned from main MCU to other each MCU
The instruction is sent out, so that all MCU enter Bootloader programs in system;
(3) MCU timer starts timing after electricity on, by user to host computer progress trigger action by selecting system
In MCU to be upgraded;
(4) host computer with transmit the frame data time it is most short determine MCU to be upgraded transmission path for target, and with this structure
Road construction is sent to main MCU by control frame, and then by main MCU by being parsed to route control frame and according to routing iinformation by road
Next MCU is passed to by control frame, transmits most that route test frame is transferred to MCU to be upgraded and sets up to be formed at last one by one according to this
Described transmission path;
(5) host computer is segmented to the code data on software upgrading, is sent to and treated by transmission path after framing
The MCU and use Retransmission timeout mechanism of upgrading;
(6) according to step (3) to (5), in Ergodic Theory it is in need carry out software upgrading MCU.
Described main MCU is the MCU that is uniquely connected with external serial ports in system.
User's selection MCU to be upgraded specific method is in described step (3):First, the most long of MCU to be upgraded is set
Selection time T, and T is averagely divided into N number of period, and make N number of period number with each MCU to correspond, N is MCU in system
Number;Then host computer starts timing, and trigger action, host computer sensing are carried out to host computer within the corresponding period by user
Period corresponding to the trigger action, the period corresponding MCU numberings are determined, and then determine the corresponding MCU of the numbering to wait to rise
The MCU of level.
Host computer most short determines to treat to transmit the frame data time according to below equation for target in described step (4)
Upgrading MCU transmission path:
Wherein:T is the time that host computer transmits frame data to MCU to be upgraded, and K is MCU to be upgraded transmission path
Hop count, LaFor the length of route test frame, unit is Byte, wherein the digital serial port for often sending 1Byte is actual to have sent 10bit
(containing parity check bit and stop position), BandiFor in MCU to be upgraded transmission path between i-th of MCU and i+1 MCU
Baud rate.
In described step (5) after MCU to be upgraded receives the code data frame of host computer transmission, to code data
Frame is verified, and then replys correct acknowledgement frame or error check frame to host computer by transmission path according to check results.
If host computer, which receives error check frame or sent code data frame, is not receiving MCU replies to be upgraded just after τ seconds
True acknowledgement frame, then retransmit code data frame by transmission path to MCU to be upgraded;
Wherein:K is the hop count of MCU to be upgraded transmission path, LbFor number most long in uplink and downlink code data frame
According to the length of frame, unit is Byte, BandiFor in MCU to be upgraded transmission path between i-th of MCU and i+1 MCU
Baud rate.
If host computer retransmits code data frame to MCU to be upgraded and does not receive the correct of MCU replies to be upgraded yet more than three times
Acknowledgement frame, then return to step (2) select new transmission path to be resumed.
MCU to be upgraded receives code data frame and performs the operation of Flash in write-in piece, until all code data frames
Whole end of transmissions, MCU to be upgraded transfers framing to by transmission path to host computer reply.
Described route test frame, code data frame, correct acknowledgement frame, error check frame and transfer in framing successively
Include frame head, numbering, length, source address, destination address, data field and CRC (CRC) and verify seven parts
Information.
MCU to be upgraded replys to transfer to host computer can restart after framing, if in the 1.5t seconds after restarting, it is upper
Machine receive that MCU to be upgraded sends on start context and the information being updated successfully, then it represents that upgrade successfully;Otherwise, then return
Step (2) selects new transmission path transmission code data again;T passes for host computer under correspondence transmission path to MCU to be upgraded
The time of defeated frame data.
The present invention point two parts composition:Host computer and slave computer (i.e. Multiple MCU System);Master system can be to slave computer system
System carries out code update, and lower computer system is then made up of multiple MCU chips, will can not interconnect reserved serial ports in design
MCU coupled, wherein the MCU being connected with external serial ports is main MCU, remaining MCU chip is sub- MCU, and each MCU has
Its unique ID.The data of host computer can imported into each chip by external serial ports.Lower computer system starts, and host computer is given
Give slave computer to enter after the order of Bootloader programs, slave computer can carry out code update.Host computer is to transmit a frame number
Most short according to the time consumed is that interpretational criteria selects data transfer path, and sets up connection.The present invention have also been devised reasonably
Data frame format, and apply during data transfer timeout mechanism and retransmission mechanism, it is ensured that whole data transfer mistake
The reliability of journey.
Because upgrading scheme of the present invention only needs to an external serial ports, for the system inside hermetically-sealed instrument, reduce
The quantity of hermetically-sealed instrument external interface, improves the airtight quality of instrument to a certain extent, while the design simply has
Effect, can be extended by serial ports, with good autgmentability.
Brief description of the drawings
Fig. 1 is the attachment structure schematic diagram between host computer and Multiple MCU System.
Fig. 2 is the structural representation of each communication frame.
Fig. 3 is the schematic flow sheet of invention software upgrade method.
Fig. 4 is the process schematic of data transfer between host computer and MCU.
Embodiment
In order to more specifically describe the present invention, below in conjunction with the accompanying drawings and embodiment is to technical scheme
It is described in detail.
Present embodiment updates the online upgrading scheme of many MCU codes based on single serial ports, by taking LPC2368 chips as an example, knot
Fig. 1 is closed to illustrate.
LPC2368 chips have 4 UART, 2 road CAN passages, 1 SPI interface, 2 synchronous serial interfaces (SSP), three
Individual I2C interfaces and an I2S interface, are very suitable for multi-path serial communication occasion, with certain representative meaning.Utilize
Bootloader program burn writings to initial address are 0 by ADS1.2 (or other ISP/IAP instruments), and termination address is 0x7FFF's
It is hexadecimal bin file by code conversion to be updated, wherein the code area for the application program upgraded in internal flash
Initial address is 0x8000.
Fig. 3 show code update process, and main upgrading scheme step is as follows:
(1) external serial ports is connected with PC serial ports, opens host computer, it is contemplated that the speed of data transfer, can be set
Baud rate is 115200, and transmission means is 8 data bit, 1 stop position, no parity, and open serial ports.To on lower computer system
Chip timer starts timing after electricity, system electrification, and some specific character string is sent in T time, such as presses Ctrl+b, leads to
Cross each chip that serial ports is connected and enter Bootloader programs.If without any action, each slave computer MCU system performs it
Internal original source program.
(2) host computer judges to need the chip number of more fresh code, code to be updated according to the time t for pressing Ctrl+b
MCU numberings as shown in formula (1).
Wherein:N is the quantity for the MCU being connected with each other by serial ports, and n is the MCU of code to be updated numbering, it is contemplated that anti-
Between seasonable, time slot Δ t=T/N setting selection is reasonable, typically selects 5s to 10s
(3) judge after the chip number that needs update, host computer sends a Route Selection frame (as shown in Figure 2) and entered automatically
Row connection, its route information is calculated by host computer according to shortest-path method.Host computer calculates biography between each chip
Time required for defeated frame code, the road of data transfer is used as using the most short path of total time required for reaching purpose chip
Footpath.If what is connected is serial ports, calculation formula is as follows:
Wherein:K is the hop count in each path, BaudiFor the baud rate between i-th of chip and i+1 chip, L is
The length of control frame, it is assumed here that the baud rate between host computer and master chip is Baud0。
(4) chip that the control frame is received in slave computer compiles the chip number included in control frame and the chip of oneself
Number contrasted, and flag bit is set, expression is laid oneself open in the route of code update, and records the data transfer path of oneself
The chip number of upper hop and next-hop.
(5) route test frame is transferred to after purpose chip, and slave computer reverse-path is successfully established.Treat that master system occurs
During alphabetical d, represent that path is set up and finish and the transmission of data can be carried out, selection needs the bin file of more fresh code, host computer
Code data is segmented, is transmitted after framing, the data frame transmitted is as shown in Figure 2.Frame head, volume are included in communication frame
Number, length, source address, destination address, seven parts in data field and CRC check.Frame head judges the beginning of a frame data, and numbering is protected
Having demonstrate,proved data will not repeat to be successfully transmitted, and source address is the ID for main MCU, and destination address is the ID of code chip to be updated, number
Be divided into 5 types according to the data in area, be respectively code data, routing iinformation, it is correct confirm, error check and the end of transmission,
And its data type mark is contained, length then may determine that the end of communication frame, and last CRC check (can also use other schools
Proved recipe formula) it ensure that data will not be transmitted mistake.
(6) each chip of lower computer system according to the routing iinformation recorded select the forwarding core of next-hop
Piece.The chip passed through in data transmission procedure performs the forwarding of data until reaching purpose chip.Because data are in forwarding
During may pass through multiple MCU, it is thus possible to occur the interruption of data or transfer check mistake etc. may, in the transmission of data
During add Retransmission timeout mechanism, most short time-out time can calculate according to formula (3).Process such as Fig. 4 of whole data transfer
It is shown.
Host computer has been sent after data τ s, if being not received by the correct confirmation with reference numeral of slave computer reply
Frame, host computer retransmits data, and slave computer receives the data frame of mistake, then replys error check frame, and host computer retransmits data, instead
It is as the same.If number of retransmissions is more than three times, then it represents that communication path is interrupted, host computer rerouting and according to data
Frame number is resumed.Chip to be updated receives the code data of transmission, performs the operation of Flash in write-in piece until number
Untill whole end of transmissions.Host computer meeting end of transmission frame after last frame code data has been sent, slave computer is to the frame
Replied, show the whole end of transmissions of code data,
After data transfer is finished, restarting systems are waited after the Δ τ times, if PC receives what all MCU were sended over
Start context+OK, then it represents that system code is updated successfully, otherwise re-execute step 2 carry out code update, wherein wait when
Between Δ τ be 1.5t, wherein t can be calculated according to formula (2).
Claims (8)
1. a kind of Multiple MCU System method for upgrading software based on single external serial ports, comprises the following steps:
(1) each MCU in Multiple MCU System is numbered and each MCU is had unique No. ID;
(2) communication mode of the setting external serial ports of Multiple MCU System and carry out upper electricity, so host computer by external serial ports to system
In main MCU be transmitted into the instructions of Bootloader programs, and then directly or indirectly should to other each MCU forwardings from main MCU
Instruction, so that all MCU enter Bootloader programs in system;
(3) MCU timer starts timing after electricity on, by user is treated by carrying out trigger action to host computer in selection system
The MCU of upgrading;
(4) host computer according to below equation with transmit the frame data time it is most short determine MCU to be upgraded transmission path for target,
And route test frame is built with this be sent to main MCU, and then by main MCU by being parsed and route control frame according to route
Route test frame is passed to next MCU by information, transmits most that route test frame is transferred to MCU to be upgraded simultaneously at last one by one according to this
Set up the transmission path described in formation;
Wherein:T is the time that host computer transmits frame data to MCU to be upgraded, and K is the hop count of MCU to be upgraded transmission path,
LaFor the length of route test frame, BaudiFor the ripple in MCU to be upgraded transmission path between i-th of MCU and i+1 MCU
Special rate;
(5) host computer is segmented to the code data on software upgrading, is sent to after framing by transmission path to be upgraded
MCU and use Retransmission timeout mechanism;
(6) according to step (3) to (5), in Ergodic Theory it is in need carry out software upgrading MCU.
2. Multiple MCU System method for upgrading software according to claim 1, it is characterised in that:User in described step (3)
The specific method for selecting MCU to be upgraded is:First, MCU to be upgraded most long selection time T is set, and T is averagely divided into N
The individual period, and N number of period is numbered one-to-one corresponding, the number that N is MCU in system with each MCU;Then host computer starts timing,
Trigger action is carried out to host computer within the corresponding period by user, host computer senses the period corresponding to the trigger action, really
Determine the period corresponding MCU numberings, and then determine that the corresponding MCU of the numbering is MCU to be upgraded.
3. Multiple MCU System method for upgrading software according to claim 1, it is characterised in that:When treating in described step (5)
The MCU of upgrading is received after the code data frame of host computer transmission, and code data frame is verified, and then according to check results
Correct acknowledgement frame or error check frame are replied to host computer by transmission path.
4. Multiple MCU System method for upgrading software according to claim 3, it is characterised in that:If host computer receives wrong true
Recognize frame or sent code data frame and do not receive the correct acknowledgement frame that MCU to be upgraded is replied after τ seconds, then by transmission path to treating
The MCU of upgrading retransmits code data frame;
Wherein:K is the hop count of MCU to be upgraded transmission path, LbFor data frame most long in uplink and downlink code data frame
Length, BaudiFor the baud rate in MCU to be upgraded transmission path between i-th of MCU and i+1 MCU.
5. Multiple MCU System method for upgrading software according to claim 4, it is characterised in that:If host computer is to MCU to be upgraded
Retransmit code data frame and do not receive the correct acknowledgement frame that MCU to be upgraded is replied yet more than three times, then return to step (2) is selected newly
Transmission path is resumed.
6. Multiple MCU System method for upgrading software according to claim 3, it is characterised in that:MCU to be upgraded receives code
Data frame simultaneously performs the operation of Flash in write-in piece, until the whole end of transmissions of all code data frames, MCU to be upgraded to
Replied by transmission path to host computer and transfer framing.
7. Multiple MCU System method for upgrading software according to claim 6, it is characterised in that:Described route test frame, generation
Code data frame, correct acknowledgement frame, error check frame and transferring include frame head, numbering, length, source successively in framing
Location, destination address, seven partial informations in data field and CRC check.
8. Multiple MCU System method for upgrading software according to claim 6, it is characterised in that:MCU to be upgraded is to host computer
Reply is transferred can restart after framing, if in the 1.5t seconds after restarting, host computer receive that MCU to be upgraded sends on version
This numbering and the information being updated successfully, then it represents that upgrade successfully;Otherwise, then return to step (2) selects new transmission path again
Transmission code data;T transmits the time of frame data for host computer under correspondence transmission path to MCU to be upgraded.
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1804799A (en) * | 2005-01-12 | 2006-07-19 | 华为技术有限公司 | SCM online loading and updating method and system |
CN101673209A (en) * | 2009-10-28 | 2010-03-17 | 广东威创视讯科技股份有限公司 | Method for updating program of multiple single chip microcomputers |
CN102866900A (en) * | 2012-08-03 | 2013-01-09 | 浙江昱能光伏科技集成有限公司 | Method and system for updating configuration data of FPGA (Field Programmable Gate Array) control unit |
CN103324501A (en) * | 2013-05-28 | 2013-09-25 | 大连理工大学 | Efficient remote updating method for node software of wireless sensor network |
CN103577233A (en) * | 2013-11-07 | 2014-02-12 | 深圳市元征科技股份有限公司 | OBDII code reading card device and system and method for upgrading same |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100532467B1 (en) * | 2003-09-18 | 2005-12-01 | 삼성전자주식회사 | MCU application program verification system providing source code level debugging using debugging information files in different versions and method thereof |
-
2014
- 2014-09-04 CN CN201410446923.XA patent/CN104281470B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1804799A (en) * | 2005-01-12 | 2006-07-19 | 华为技术有限公司 | SCM online loading and updating method and system |
CN101673209A (en) * | 2009-10-28 | 2010-03-17 | 广东威创视讯科技股份有限公司 | Method for updating program of multiple single chip microcomputers |
CN102866900A (en) * | 2012-08-03 | 2013-01-09 | 浙江昱能光伏科技集成有限公司 | Method and system for updating configuration data of FPGA (Field Programmable Gate Array) control unit |
CN103324501A (en) * | 2013-05-28 | 2013-09-25 | 大连理工大学 | Efficient remote updating method for node software of wireless sensor network |
CN103577233A (en) * | 2013-11-07 | 2014-02-12 | 深圳市元征科技股份有限公司 | OBDII code reading card device and system and method for upgrading same |
Non-Patent Citations (1)
Title |
---|
水下移动平台数据采集和传输系统设计;杨海波;《传感技术学报》;20140331;第362-365页 * |
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