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Diffstat (limited to 'src/jtag/drivers/OpenULINK/README')
-rw-r--r-- | src/jtag/drivers/OpenULINK/README | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/src/jtag/drivers/OpenULINK/README b/src/jtag/drivers/OpenULINK/README new file mode 100644 index 00000000..445d7703 --- /dev/null +++ b/src/jtag/drivers/OpenULINK/README @@ -0,0 +1,34 @@ +This is the OpenULINK firmware for the Keil ULINK JTAG adapter. + +The main components of the Keil ULINK adapter are: +- Cypress EZ-USB microcontroller: enhanced 8051 CPU + USB core (1.1 Full-Speed) +- SRAM memory chip +- Level shifters to support different JTAG signal voltage levels +- Pin headers for various JTAG pin assignments + +This firmware can only be run on the ORIGINAL Keil ULINK adapter, not on the +newer ULINK2, ULINK-ME or ULINK-PRO, as these adapters are based on different +hardware. + +To compile the firmware, the SDCC compiler package is required. Most Linux +distributions include SDCC in their official package repositories. The SDCC +source code can be found at http://sdcc.sourceforge.net/ +Simply type "make hex" in the OpenULINK directory to compile the firmware. +"make clean" will remove all generated files except the Intel HEX file required +for downloading the firmware to the ULINK adapter. + +Note that the EZ-USB microcontroller does not have on-chip flash, nor does the +Keil ULINK include on-board memory to store the firmware program of the EZ-USB. +Instead, upon initial connection of the ULINK adapter to the host PC via USB, +the EZ-USB core has enough intelligence to act as a stand-alone USB device, +responding to USB control requests and allowing firmware download via a special +VENDOR-type control request. Then, the EZ-USB microcontroller simulates a +disconnect and re-connect to the USB bus. It may take up to two seconds for the +host to recognize the newly connected device before OpenOCD can proceed to +execute JTAG commands. This delay is only visible when OpenOCD first uses a +blank (unconfigured) ULINK device. + +Once the user disconnects the ULINK adapter, all its memory contents are lost +and the firmware download process has to be executed again. This also maintains +compatibility with the original Keil uVision IDE, which will happily download +its own firmware image to a blank ULINK adapter. |