【正文】 argument for os_wait is a timeout, where the currentlyexecuting task is interrupted for the specified number of timer ticks. Thefollowing uses timeouts for the time delay. Program with os_wait Function This program is similar to the previous example with the exception that job0 isinterrupted with os_wait after counter0 has been incremented. RTX51 waitsthree timer ticks until job0 is ready for execution again. During this time, job1 isexecuted. This function also calls os_wait with a timeout of 5 ticks. The result:counter0 is incremented every three ticks and counter1 is incremented every fivetimer ticks. Wait for Signal Another event for os_wait is a signal. Signals are used for task coordination: ifa task waits with os_wait until another task issues a signal. If a signal waspreviously sent, the task is immediately continued. Program with Wait for Signal. In this example, task 1 waits for a signal from task 0 and therefore processes theoverflow from counter0. Preemptive Task Switching The full version of RTX51 provides preemptive task switching. This feature isnot included in RTX51 Tiny. It is explained here to provide a pleteoverview of multitasking concepts. In the previous example, task 1 is not immediately started after a signal hasarrived, but only after a timeout occurs for task 0. If task 1 is defined with ahigher priority than task 0, by means of preemptive task switching, task 1 isstarted immediately after the signal has arrived. The priority is specified in thetask definition (priority 0 is the default value). RTX51 Technical Data Description RTX51 Full RTX51 Tiny Number of tasks 256。結(jié)果，只有在沒有軟件調(diào)試工具的情況下它才會(huì)對(duì)你有用。 注意：調(diào)試技巧 3：有時(shí)可能需要同時(shí)觀察運(yùn)行著嵌入式軟件的目標(biāo)板上電信號(hào)的一個(gè)子集。因?yàn)樗麄冎荒懿榭葱盘?hào)處理器以外的 錯(cuò)誤 ，但是，他們無法控制你的像一個(gè)調(diào)試器或仿真器軟件可以執(zhí)行流程。盡管模擬器有很多不足，它在項(xiàng)目的早期特別是沒有任何實(shí)際的硬件可以用來試驗(yàn)程序的時(shí)候就相當(dāng)有用。對(duì)于嵌入式處理器，它就像一個(gè)只讀存儲(chǔ)芯片，而對(duì)于遠(yuǎn)程調(diào)試器，它又像 一個(gè)調(diào)試器。例如，你可以對(duì)事件“當(dāng)變量 foo 等于 15 同時(shí) AX寄存器等于 0”設(shè)置一個(gè)硬件斷點(diǎn)。某些情況下，甚至能使用相同的前端調(diào)試器。 使用標(biāo)準(zhǔn)的 Turbo Debugger 命令，你可以單步執(zhí)行程序、設(shè)置斷點(diǎn)、監(jiān)控變量和寄存器的值、做調(diào)試器允許的任何事。這里我們?cè)僖淮问褂昧顺绦虻目芍囟ㄖ钒姹荆驗(yàn)槲覀円殉绦蛳螺d到 RAM 里并在那里執(zhí)行它。39。表 41顯示了命令格式和一些主要的命令。它監(jiān)控和主機(jī)的通信鏈路并對(duì)遠(yuǎn)程調(diào) 試器的請(qǐng)求做出回應(yīng)。 遠(yuǎn)程調(diào)試器 如果可能的話，一個(gè)遠(yuǎn)程調(diào)試器可以通過主機(jī)和目標(biāo)機(jī)之間的串行網(wǎng)絡(luò)連接來下載、執(zhí)行和調(diào)試嵌入式軟件。 Ar 電路板 特殊的在線可編程存儲(chǔ)器，叫做快閃存儲(chǔ)器（簡稱閃存），它可以在不從板上移走的情況下編 程。這個(gè)地址叫做復(fù)位地址，位于那里的指令就叫復(fù)位代碼。這樣，可執(zhí)行二進(jìn)制映像文件就很容易傳給它來對(duì) ROM 芯片編程。首先把映像文件傳到編程器，然后把存儲(chǔ)器芯片插入大小形狀何時(shí)的插座里并沖編程器屏幕上的菜單里懸著芯片的型號(hào)。 如果你的程序看起來像是沒有正確運(yùn)行，那可能是你復(fù)位代碼出了問題。實(shí)際上，板上的另外一塊存儲(chǔ)器中已經(jīng)包含了可以對(duì)這個(gè)快閃存儲(chǔ)器編程的功能。一個(gè)遠(yuǎn)程調(diào)試器的前端和你可能用過的其他調(diào)試器都一樣，通常有一個(gè)基于文本或 GUI（圖形用戶 界面）的主窗口和幾個(gè)小一點(diǎn)的窗口來顯示正在運(yùn)行的程序的源代碼、寄存器內(nèi)容和其他相關(guān)信息。當(dāng)然，這些請(qǐng)求和監(jiān)控器的響應(yīng)必須符合某種預(yù)先定義好的通信協(xié)議，而且這些協(xié)議通常是很底層的。這些命令示范了發(fā)生在典型的遠(yuǎn)程調(diào)試器前端和調(diào)試器之間的交互類型。... download size 750H bytes (2K) Checking COM1 (press ESC key to exit)... Remote ident: TDR188EB version Download successful Sending 39。調(diào)試器啟動(dòng)選項(xiàng) rpl 和rp3 設(shè)置了到調(diào)試監(jiān)控器的通信鏈路的參數(shù)?；蛘呖梢园聪?F9立即運(yùn)行程序的剩下部分、這樣做了以后，你就能看到板上的綠色 LED 開始閃爍了。但是仿真器有自己的目標(biāo)處理器，所以就有可能實(shí)時(shí)的 監(jiān)視和控制處理器的狀態(tài)。 在線仿真器的另一種有用的特性是實(shí)時(shí)跟蹤，典型地仿真包含了大塊的專用RAM， 專門用來存儲(chǔ)執(zhí)行過的每一個(gè)指令周期的信息。 ROM 仿真器相比調(diào)試監(jiān)控器有如下幾個(gè)優(yōu)點(diǎn)。 注意：調(diào)試技巧 2：如果曾經(jīng)遇到目標(biāo)處理器從不同于你認(rèn)為應(yīng)該的數(shù)據(jù)手冊(cè)里讀取數(shù)據(jù)，嘗試在模擬器上運(yùn)行相同的軟件。這使得這些工具本身明顯用處不大。例如：你可能想觀察處理器和它所連一個(gè)外設(shè)的總線交互信號(hào)。 附件 2：外文原文 （復(fù)印件） RTX51 RealTime Operating System RTX51 is a multitasking realtime operating system for the 8051 family. RTX51simplifies system and software design of plex and timecritical is a powerful tool to manage several jobs (tasks) on a single CPU. Thereare two distinct versions of RTX51: RTX51 Full which performs both roundrobin and preemptive task switchingwith 4 task priorities and can be operated with interrupt functions in supports signal passing。 max. 19 tasks active 16 RAM requirements 40 .. 46 bytes DATA 20 .. 200 bytes IDATA 7 bytes DATA 3 * task count IDATA (user stack) min. 650 bytes XDATA Code requirements 6KB .. 8KB 900 bytes Hardware requirements timer 0 or timer 1 timer 0 System clock 1000 .. 40000 cycles 1000 .. 65535 cycles Interrupt latency 50 cycles 20 cycles Context switch time 70 .. 100 cycles (fast task) 180 .. 700 cycles (standard task) depends on stack load 100 .. 700 cycles depends on stack load Mailbox system 8 mailboxes with 8 integer entries each not available Memory pool system up to 16 memory pools not available Semaphores 8 * 1 bit not available Overview of RTX51 Routines The following table lists some of the RTX51 functions along with a briefdescription and execution timing (for RTX51 Full). function Description CPU Cycles sr_recv_message Receive a message (call from interrupt). 71 (with message) isr_send_message Send a message (call from interrupt). 53 isr_send_signal Send a signal to a task (call from interrupt). 46 os_attach_interrupt Assign task to interrupt