【正文】 件下載到嵌入式系統(tǒng)運行了，可執(zhí)行二進制影響一般是要下載到目標板上的存儲器里并在那里執(zhí)行，并且如果你配備了適當(dāng)?shù)墓ぞ叩脑?，還可以在程序里設(shè)置斷點或以一種不干擾的方式來觀察運行情況，本章介紹了可用于下載，運行和調(diào)試嵌入式軟件是各種技術(shù)。應(yīng)該在插入芯片之前關(guān)掉電源，插入之后在打開。 注意 :調(diào)試技巧 1：一個最簡單的調(diào)試技巧就是利用 LED 來指示成功或者失敗。隨板提供的“ Target188EB Monitor User’ s Manual”包含了把一個 Intel 十六進制格式文件，比如 ，載入到閃存里的指令。前端運行在主機上并提供前述的人機界面。 GUN 調(diào)試器（ gdb）就是這樣一個調(diào)試器，像其他 GUN 工具一樣，它一開始是被設(shè)計用來完成本機調(diào)試，后來才具有了跨平臺調(diào)試的能力。嵌入式軟件開發(fā)人員已經(jīng)有了所需的主機 了，任何一個遠程調(diào)試器的價格并不會在全套跨平臺開發(fā)工具（編譯器、連接器、定址器等等）的價格上增加多少，還有調(diào)試器的供應(yīng)商們通常會提供他們的調(diào)試監(jiān)控器的源代碼，以增加他們的用戶群。在這種情況下，我們也許會以可重定址程序來開始，那么 tload 工具也會自動地在 RAM里第一個可利用的地址處為我們的程序重新定址。如果沒成功的話，可能是串行連接出了問題。實際上， ICE取代了（或者仿真了）目標板上的處理器。不過這些軟斷點只能到指令提取級別，也就是相當(dāng)于“在提取該指令前停止運行”。 ROM仿真器 另外一種仿真器也值得在這里提一下。最后， ROM 仿真器完全替代了原有的 ROM，所以不會占用目標板的存儲空間來容納調(diào)試監(jiān)控器代碼。 到目前為止，一個模擬器最大的缺點是它僅能模擬處理器 ，而且 嵌入式系統(tǒng)經(jīng)常包含一 個或多個其他重要設(shè)備。它會有幾十個甚至上百 個輸入，它們分別只用來做一件事：它所連接的電信號的邏輯電平是 1還是0。例如，你可以使一個空閑的 I/O 引腳從 0到 1，然后邏輯分析儀就可以設(shè)置成響應(yīng)這個使勁的觸發(fā)器并開始捕獲后續(xù)的所有情況。 signal from task or interrupt。 the following events are possible (also in bination): Event Timeout: the task Timer is set to the duration is specified with the os_wait function call. After the Timer decrements to zero, the task goes into Ready state. Interval: the time interval specified with os_wait is added to the task Timer value. After the Timer decrements to zero, the task goes into Ready state. Signal: the os_wait function was called with K_SIG and the task waits for Sig = 1. Sig status of the Signal bit that is assigned to this task. Timer value of the Timer that is assigned to this task. The Timer value decrements with every RTX system timer tick. If the Timer bees zero and the task is waiting for Timeout or Interval the task goes into Ready state. Stack value of the stack pointer (SP) that is used when this task is Running. RTX51 Tiny contains an efficient stack management that is explained in the RTX51 Tiny User’sGuide, Chapter 5: RTX51 Tiny, Stack Management. This manual provides detailed information about the Stack value. S 狀態(tài) 描述 Deleted Tasks that are not started are in the Deleted state. Ready Tasks that are waiting for execution are in the Ready state. After the currently Running task has finished processing, RTX starts the next task that is in the Ready state. Running The task currently being executed is in the Running state. Only one task is in the Running state at a time. Timeout Tasks that were interrupted by a roundrobin timeout are in the Timeout state. This state is equivalent to Ready。 signal from task or rest of this section uses RTX51 to refer to RTX51 Full and RTX51 between the two are stated where applicable. Introduction Many microcontroller applications require simultaneous execution of multiplejobs or tasks. For such applications, a realtime operating system (RTOS) allowsflexible scheduling of system resources (CPU, memory, etc.) to several implements a powerful RTOS that is easy to use. RTX51 works withall 8051 derivatives. You write and pile RTX51 programs using standard C constructs andpiling them with C51. Only a few deviations from standard C are requiredin order to specify the task ID and priority. RTX51 programs also require thatyou include the or header file. When you select in theμVision2 dialog Options for Target Target the operating system, the linker addsthe appropriate RTX51 library file. Single Task Program A standard C program starts execution with the main function. In an embeddedapplication, main is usually coded as an endless loop and can be thought of as asingle task that is executed continuously. For example: RoundRobin Task Switching RTX51 Tiny allows a quasiparallel, simultaneous execution of several task is executed for a predefined timeout period. A timeout suspends theexecution of a task and causes another task to be started. The following exampleuses this roundrobin task switching technique. Simple C Program using RTX51 RTX51 starts the program with task 0 (assigned to job0). The functionos_create_task marks task 1 (assigned to job1) as ready for execution. Thesetwo functions are simple count loops. After the timeout period has beenpleted, RTX51 interrupts job0 and begins execution of job1. This functioneven reaches the timeout and the system continues with job0. The os_wait Function The os_wait function provides a more efficient way to allocate the availableprocessor time to several tasks. os_wait interrupts the execution of the currenttask and waits for the specified event. During the time in which a task waits foran event, other tasks can be executed. Wait for Timeout RTX51 uses an 8051 timer in order to generate cyclic interrupts (timer ticks).The simplest event