第08章 中断系统和CPU定时器的使用.ppt

C28x 中断源 C28X DSP 的中断源 8.2 Peripheral Interrupt Expansion - PIE PIE 寄存器 8.3 可屏蔽中断处理过程 中断标志寄存器 (IFR) 中断使能寄存器 (IER) 中断全局使能 INTM用来做全局的使能/禁止中断: 使能: INTM = 0 禁止: INTM = 1 (reset value) INTM只能被汇编语言修改: 中断响应过程 8.4 中断向量 8.4 中断向量 8.4 中断向量 8.4 中断向量 TMS320F2812 内存映射 复位时默认中断向量表 PIE Vector Mapping (ENPIE = 1) F2812/10 PIE Interrupt Assignment Table Device Vector Mapping - Summary 8.5 复用中断处理的注意事项（略）（见教科书上的8.4节 中断源 部分） 8.6 定时器中断应用举例 定时器中断应用举例 定时器中断应用举例 本章小结 F2812的中断源及类型 F2812中断源的扩展原理 F2812中断向量的分配和映射方式 简述F2812可屏蔽中断的处理过程 定时器的工作原理及中断应用 C28x CPU的中断源分类 C28x 中断处理的一般过程 C28x 中断处理过程 1. 定时器控制寄存器（TCR） 2. 定时器预定标寄存器（TPR） 3. 定时器计数器（TPR） 4. 定时器周期寄存器（PRD） At the CPU level, each of the C28x interrupts, whether hardware or software, can be placed in one of the following two categories: Maskable interrupts.These are interrupts that can be blocked (masked) or enabled (unmasked) through software. Nonmaskable interrupts. These interrupts cannot be blocked. The C28x will immediately approve this type of interrupt and branch to the corresponding subroutine. All software-initiated interrupts are in this category. The C28x handles interrupts in four main phases: Receive the interrupt request. Suspension of the current program sequence must be requested by a software interrupt (from program code) or a hardware interrupt (from a pin or an on-chip device). Approve the interrupt. The C28x must approve the interrupt request. If the interrupt is maskable, certain conditions must be met in order for the C28x to approve it. For nonmaskable hardware interrupts and for software interrupts, approval is immediate. The C28x handles interrupts in four main phases: 3) Prepare for the interrupt service routine and save register values. 4) Execute the interrupt service routine. The C28x branches to its corresponding subroutine called an interrupt service routine (ISR). The C28x branches to the address (vector) you store at a redetermined vector location and executes the ISR you have written. 2005.8 第8章 TMS3