tony0716

Overview of HP-UX

Path names
There are two kinds of pathnames: absolute and relative

cd /users/user4/class_bd
        change directory to /users/user4/class_bd
ls fixture
        list, short the relative directory fixture
ls /users/user4/class_bd/fixture
        list, short the absolute directory fixture
cd ..
        change directory to the parent directory
ls
        list, short the current directory
ls .
        list, short the current directory
pwd
        present work directory is given: /users/user4
ll
        print the long listing of the current or specified directory
lsf
        print the short list of the current or specified directory, but also include a flag on directories and executable files
who
        report the logon name of all users currently on the system
whoami
        tells you who you currently logon’ed on as
hostname
        displays the name of the computer you are currently on
cd /
etc/shutdown
rm –r         remove the file

tony0716

上面这些都是比较基本的东东,希望能给那些新手一些帮助.

tony0716

下面讲点B-scan.

tony0716

[upload=bmp]uploadImages/2004326134741.bmp[/upload]

tony0716

At the device level, the boundary-scan elements contribute nothing to the functionality of the internal logic. In fact, the boundary-scan path is independent of the function of the device. The value of the scan path is at the board level as shown in Figure 11.
The figure shows a board containing four boundary-scan devices. Notice that there is an edge-connector input called TDI connected to the TDI of the first device. TDO from the first device is permanently connected to TDI of the second device, and so on, creating a global scan path terminating at the edge connector output called TDO. TCK is connected in parallel to each device TCK input. TMS is connected in parallel to each device TMS input.

tony0716

[upload=bmp]uploadImages/2004326135546.bmp[/upload]

tony0716

What the tester sees from the edge connector is simply the concatenation of the various boundary-scan registers – that is, a single register that provides access to all device outputs now considered to be drivers (sometimes called a transmitter) onto an interconnect and all device inputs now considered to be sensors (sometimes called a receiver) from the interconnect – see Figure 12.
In this way, particular tests can be applied across the device interconnects via the global scan path by loading the stimulus values into the appropriate device-output scan cells via the edge connector TDI (shift-in operation), applying the stimulus across the interconnects (update operation), capturing the responses at device-input scan cells (capture operation), and shifting the response values out to the edge connector TDO (shift-out operation).
Essentially, boundary-scan cells can be thought of as virtual nails, having an ability to set up and apply tests across the interconnect structures on the board.

tony0716

[upload=bmp]uploadImages/2004326135910.bmp[/upload]

tony0716

Figure 13 shows a basic universal boundary-scan cell, known as a BC_1. The cell has four modes of operation: normal, update, capture, and serial shift. The memory elements are two D-type flip-flops with front-end and back-end multiplexing of data. (As with all circuits in this tutorial, it is important to note that the circuit shown in Figure 13 is only an example of how the requirement defined in the Standard could be realized. The IEEE 1149.1 Standard does not mandate the design of the circuit, only its functional specification.)
During normal mode, Data_In is passed straight through to Data_Out.
During update mode, the content of the Update Hold cell is passed through to Data_Out.
During capture mode, the Data_In signal is routed to the input Capture Scan cell and the value is captured by the next ClockDR. ClockDR is a derivative of TCK.
During shift mode, the Scan_Out of one Capture Scan cell is passed to the Scan_In of the next Capture Scan cell via a hard-wired path.
Note that both capture and shift operations do not interfere with the normal passing of data from the parallel-in terminal to the parallel-out terminal. This allows on the fly capture of operational values and the shifting out of these values for inspection without interference. This application of the boundary-scan register has tremendous potential for real-time monitoring of the operational status of a system — a sort of electronic camera taking snapshots — and is one reason why TCK is kept separate from any system clocks.

tony0716

[upload=bmp]uploadImages/2004326140345.bmp[/upload]

tony0716

The Figure shows the following elements:
  A set of four dedicated test pins — Test Data In (TDI), Test Mode Select (TMS), Test Clock (TCK), Test Data Out (TDO) — and one optional test pin Test Reset (TRST*). These pins are collectively referred to as the Test Access Port (TAP).
  A boundary-scan cell on each device primary input and primary output pin, connected internally to form a serial boundary-scan register (Boundary Scan).
  A finite-state machine TAP controller with inputs TCK, TMS, and TRST*.
  An n-bit (n >= 2) Instruction register, holding the current instruction.
  A 1-bit Bypass register (Bypass).
  An optional 32-bit Identification register capable of being loaded with a permanent device identification code.

tony0716

一口气发了很多资料,累了.
下次在发,先让大家消化一下吧,哈哈......

tony0716

大家一起来参与啊,有资料的朋友请不要吝惜嘛...

tony0716

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wujinhua

有给我发一个
E-mail:wujonhua@yahoo.com.cn