Parallel Cable III

Figure 2-6 Top and Bottom View of Parallel Download Cable III

The Parallel Download Cable III consists of a cable assembly containing logic to protect your PC's parallel port and a set of headers to connect to your target system. PC III is replaced by PC IV in March 2002 with legacy support from iMPACT.

Using the Parallel Download Cable requires a PC equipped with an AT compatible parallel port interface with a DB25 standard printer connector. Figure 2-1 shows the Parallel Download Cable.

Connecting for System Operation

Connect the parallel cable to the host system and your target system.

Figure 2-7 Parallel Download Cable III and Accessories

The parallel download cable can download to a single device or several devices connected in either a boundary-scan chain or a slave-serial daisy chain (FPGA only). The parallel cable can also be used to read back configuration and boundary-scan data.

The transmission speed of the Parallel Download Cable is determined solely by the speed at which the host PC can transmit data through its parallel port interface.

Figure 2-8 Parallel Download Cable Connection to JTAG Boundary-scan TAP

JTAG parallel cable schematic contains schematic diagrams of the Parallel Download Cable.

Table 2-5 Parallel Cable Connections and Definitions

Name	Function	Connections
VCC	Power - Supplies VCC (5 V, 3.3V, or 2.5V, 10 mA, typically) to the cable.	To target system VCC
GND	Ground - Supplies ground reference to the cable.	To target system ground
TCK	Test Clock - this clock drives the test logic for all devices on boundary-scan chain.	Connect to system TCK pin.
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.
TMS	Test Mode Select - this signal is decoded by the TAP controller to control test operations.	Connect to system TMS pin.

Serial Configuration Connection

Figure 2-9 Parallel Cable III Connections

Table 2-6 Parallel Cable Connections and Definitions

Name	Function	Connections
VCC	Power - Supplies VCC (5 V, 3.3V, or 2.5V, 10 mA, typically) to the cable.	To target system VCC
GND	Ground - Supplies ground reference to the cable.	To target system ground
CCLK	Configuration Clock --- is the configuration clock pin, and the default clock for readback operation.	Connect to system CCLK pin.
DONE (D/P)	Done/Program --- Indicates that configuration loading is complete, and that the start-up sequence is in progress.	Connect to system DONE pin.
DIN	Data In --- Provides configuration data to target system during configuration and is tristated at all other times.	Connect to system DIN pin.
PROG	Program --- A Low indicates the device is clearing its configuration memory. Active Low signal is used to initiate the configuration process.	Connect to system PROG pin.