gres
Full Member level 4
JTAG-lock-pick is a JTAG for processors with ARM core. Connect to computer via USB. This project based on project by Amontec name - JTAGkey. Tool works thanks to FTDI FT2232 chip set, with is double channel USB converter <=> UART/FIFO. At first channel chipset gives JTAG interface, at second, full interface UART/RS-232 (RXD, TXD, RTS, CTS, DCD, DSR, DTR,RI) with possibility to add RS-485 converter. The JTAG-lock-pick was made us uncompromising, powerful solution, that can use all abilities of chipsets.
JTAG interface allow to reach clock frequency up to 6MHz. Thanks to USB bus device could be connect to any PC. Very advanced buffer store from 74LVC series, let to communicate with device powered by different voltage from about 1,6 V to 5,5 V.
One of guidelines of project was share both UART and RS-232 interface. Four most important lines of UART interface (RXD, TXD, RTS, CTS) are also buffering by 74LVC system. Other lines are steering directly via FT2232 system - output signals are about 5V, however threshold of "logic one" for input signals are 1,6V. choose betwen RS-232 and UART interface is automatic, based on UART stering voltage - if voltage is higher then 1,7V ,UART interface were active. Thanks to TXDEN signal on UART interface, it is possible to join RS-485 conventer.
Designed chipset allow to powered buffor systems by JTAG/UART slots from PC with 3,3V or 5V.
As I said JTAG-lock-pick is based on JTAGkey thats why they are compatible. Both of them have split lines SRST and TRST, that you can configure to work at push-pull or open-drain mode.
A lot useful application you can download from Amontec web.
more information at https://www.elektroda.pl/rtvforum/viewtopic.php?t=1419102&highlight=jtag+lock+pick&sid=