To improve data transmission rate of JTAG interface, instruction register and related control logic are redesigned. 为了提高JTAG接口的数据传输效率,指令寄存器(IR)和相关控制逻辑被重新设计。
The collection of instructions is implemented as patterns, each one of which has a different meaning when loading into the instruction register. 指令集合实现为位模式,每个位模式装入测试寄存器时具有不同意义。
Control unit ( controller ): Control unit is composed of program arithmometer, instruction register and operation controller, ect. 控制器:控制器是由程序计数器、指令寄存器(IR)和操作控制器等组成。
The boundary scan adopts the address, data, control register together with instruction register to access relevant space, utilizes original circuit of core of DSP, decreases the cost of hardware; 在边界扫描链设计中,采用了自定义的控制、数据、地址寄存器与指令寄存器(IR)相结合的访问ROM和RAM等相应空间方法,与原有的地址译码电路相结合,减少了硬件的开销;
Based on the driver of JTAG, a set of functions is provided including data / instruction register reading / writing, chain selecting, bypassing and resetting to the caller. 首先在驱动层的基础上实现JTAG操作接口,该接口向调用者提供读写数据、指令寄存器(IR),读取控制器标识,设置扫描链及重启等功能函数。