AI-JTAGOPTO-1 STMicroelectronics

UM0378 User manual JTAG opto-isolation board Introduction The JTAG opto-isolation (AI-JTAG/OPTO-1) board can be connected between development tools and an application board to provide electrical isolation. This is essential when the development tools are not connected to the same ground as the application. It is also useful to protect the development tools from electrical spikes that often occur in some applications, such as motor control applications. The JTAG opto-isolation board can be used with any tools that use the 20-pin JTAG standard connection for in-circuit debugging and programming of ST ARM core-based microcontrollers. Figure 1. JTAG opto-isolation board Features 1kV DC isolation Supports 3.3V or 5V operation, configurable by solder bridge Powered from target application using DC/DC converter powered by 3.3V or 5V JTAG standard 20-pin connection supporting TRST, TDI, TMS, TCK, RTCK, TDO, RESET signals 3.3V or 5V CMOS level compatibility 40nS maximum propagation delay for all unidirectional signals Power consumption on target application power supply less than 200mA February 2007 Rev 1 1/9 www.st.comHOST Connector Hardware layout and configuration UM0378 1 Hardware layout and configuration The JTAG opto-isolation board uses high speed optocouplers that allow a very low propagation time between input and output (typically 30nS). The board includes: a JTAG standard 20-pin female HOST connector (J1) that allows direct connection of the development tool, a JTAG standard 20-pin male TARGET connector (J2) for connection of the application board. The opto-isolation board is delivered with a 7cm, 20-pin flat cable with JTAG standard connectors to facilitate the connection to the application board. The hardware block diagram shown in Figure 2 illustrates the functional connections between the development tool (HOST) and the application (TARGET). Figure 3 will help you locate main features on the JTAG opto-isolation board. Figure 2. Functional block diagram RESET RESET TRST TRST TDI TDI TMS TMS TCK TCK RTCK RTCK TDO TDO Power DC/DC supply converter For more detailed information on functional connections on the board, refer to Figure 5 on page 6, and to Figure 6 on page 7. 2/9 TARGET Connector