Real-Time Embedded Multithreading Using ThreadX and MIPS- P23 pps

... *suspended_count, TX_BYTE_POOL **next_pool); 1 ThreadX is a registered trademark of Express Logic, Inc. The ThreadX API, associated data structures, and data types are copyrights of Express Logic, ... 90 Thread scheduling , 59 – 65 Thread state transition , 89 ThreadX initialization , 56 , 58 – 9 ThreadX interrupt handling , 65 – 8 , 69 Tick counter , 154 Time servic...

Ngày tải lên: 03/07/2014, 05:20

... empty and another thread is suspended because it is waiting for a message, then that message bypasses the queue entirely and goes directly to the destination specifi ed by the other thread. ThreadX ... case study based on an application that could use both the ThreadX RTOS and the ARM processor. The application we will consider is a real-time video/audio/motion (VAM) recording...

Ngày tải lên: 03/07/2014, 05:20

... initialization and to process routine data. 14.4 Design of the System Our design will be simplifi ed and will concentrate on control issues. In this section, we will consider thread design issues, and ... processes will handle 4 the actual storing and copying of data. 14.4.1 Thread Design We need a thread to perform various initialization duties such as setting pointers an...

Ngày tải lên: 03/07/2014, 05:20

... required. The following are valid selections: TX _AND (0ϫ 02) TX _AND_ CLEAR (0 ϫ 03) TX_OR (0 ϫ 00) TX_OR_CLEAR (0 ϫ 01) Selecting TX _AND or TX _AND_ CLEAR specifi es that all event fl ags must ... Initialization, threads, timers, and ISRs Preemption Possible Yes Example TX_EVENT_FLAGS_GROUP my_event_group; UINT status; … /* Set event fl ags 0, 4, and 8. */ st...

Ngày tải lên: 03/07/2014, 05:20

... equipment. 2 1.2 What is an Embedded System? In recent years, the line between embedded and nonembedded systems has blurred, largely because embedded systems have expanded to a vast array of ... control to ThreadX (and does not return!). ThreadX performs initialization of various internal data structures and then processes the application defi nitions and the thread ent...

Ngày tải lên: 03/07/2014, 05:20

... variety of services to the developer of real-time embedded systems. These services allow the developer to create, manipulate, and manage system resources and entities in order to facilitate application ... has a higher priority and becomes ready for execution. ThreadX then interrupts Thread 1 and gives Thread 2 control of the processor. When Thread 2 completes its work, Thr...

Ngày tải lên: 03/07/2014, 05:20

... interrupt-handling software no longer has to determine which interrupt source caused the interrupt. 6.2 ThreadX Implementation of MIPS Exception Handling ThreadX is a popular RTOS for embedded ... interrupt processing, and others are for handling program exceptions. The EXL, ERL, and UM of the Status Register defi ne the current processor mode. Figure 5.8 shows these values a...

Ngày tải lên: 03/07/2014, 05:20

... thread. 6.2.3 ThreadX Interrupt Handling ThreadX provides basic handling for all MIPS program exceptions and interrupts. The ThreadX program exception handlers are small spin loops that enable ... $26,_tx_exception_handler # Pickup exception handler address j $26 # Jump to exception handler nop # Delay slot These instructions jump to _tx_exception_handler , the ThreadX MIPS exc...

Ngày tải lên: 03/07/2014, 05:20

... other threads, create priority inversion, reduce processing bandwidth, and make the application’s run-time behavior diffi cult to understand. If thread starvation is a problem, an application can ... thread has priority 15 and a preemption-threshold of 0, will another thread with priority 5 be able to preempt it? 10 Explain the difference between time-slicing and cooperative multithr...

Ngày tải lên: 03/07/2014, 05:20

... allocates and deallocates from a memory block pool — it always allocates and deallocates at the head of the available list. This provides the fastest possible linked list processing and might ... Memory Block Pools Allocating memory in a fast and deterministic manner is essential in real-time applications. This is made possible by creating and managing multiple pools of fi xed...

Ngày tải lên: 03/07/2014, 05:20