The XChecker hardware consists of a cable assembly with internal logic, a test fixture, and a set of headers to connect the cable to your target system.
Using the XChecker hardware requires either a standard DB-9 or DB-25 RS-232 serial port. If you have a different serial port connection, you need to provide the appropriate adapter. “XChecker Hardware and Accessories” figure shows the XChecker cable hardware and accessories.
The XChecker cable can be used with a single CPLD or several devices connected in a boundary-scan chain to download and readback configuration and boundary-scan data.
Figure 2.1 XChecker Hardware and Accessories |  |
“XChecker Cable” figure shows top and bottom views of the XChecker cable.
Figure 2.2 XChecker Cable | |
Figure 2.3 XChecker Connections to JTAG Boundary-scan TAP | |
“XChecker Cable Connections and Definitions” table describes the pin connections to the target circuit board.
| Name | Function | Connections |
|---|---|---|
| VCC | Power - Supplies VCC (5 V, 100 mA, typically) to the cable. | To target system VCC |
| GND | Ground - Supplies ground reference to the cable. | To target system ground |
| RD (TDO) | Read Data - Read back data from the target system is read at this pin. | Connect to system TDO pin. |
| TDI | Test Data In - this signal is used to transmit serial test instructions and data. | Connect to system TDI pin. |
| TCK | Test Clock - this clock drives the test logic for all devices on boundary-scan chain. | Connect to system TCK pin. |
| TMS | Test Mode Select - this signal is decoded by the TAP controller to control test operations. | Connect to system TMS pin. |
| CLKI | Not used. | Unconnected. |
| CLKO | Not used. | Unconnected. |
| CCLK | Not used. | Unconnected. |
| D/P | Not used. | Unconnected. |
| DIN | Not used. | Unconnected. |
| PROG | Not used. | Unconnected. |
| INIT | Not used. | Unconnected. |
| RST | Not used. | Unconnected. |
| RT | Not used. | Unconnected. |
| TRIG | Not used. | Unconnected. |
The XChecker Cable supports Baud rates as shown in Table 2-2.
| Platform | 9600 | 19200 | 38400 |
|---|---|---|---|
| IBM PC | X | X | X |
| SUN | X | X | X |
| HP 700 | X | X | X |
There are two simple steps for connecting the cable:
The XChecker cable connects to your system RS-232 serial port. You may need a DB-9/DB-25 adapter, which accommodates most serial ports, so that you can connect the XChecker cable to your host system.
The JTAG Programmer software will automatically identify the XChecker cable when correctly connected to your computer. If you choose to, you may also select this connection manually. To set up a serial port manually:
Output 
Cable Setup
Select XChecker, then click on OK. If you are using the XChecker Cable you may also select a BAUD rate. See Table 2-1, Valid Baud Rates.
The XChecker cable draws its power from the target system through VCC and GND. Therefore, power to XChecker, as well as to the target system, must be stable. Do not connect any signals before connecting VCC and ground.
If your system`s power is turned off before or during JTAG Programmer operations, the cable will not operate. Your system's power should be on during JTAG Programming operations.
If the power has been momentarily interrupted, go to Output Cable Reset to reinitialize the XChecker cable. If you do not want to operate at maximum Baud rate, go to the Cable Communication Setup dialog box (Output Cable Setup...) and set a lower rate.
