38 lines
1.7 KiB
Plaintext
38 lines
1.7 KiB
Plaintext
#SPDX-License-Identifier: GPL-2.0-or-later
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This is the ANGIE firmware for ANGIE USB-JTAG adapter.
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The main components of ANGIE adapter are:
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- Cypress EZ-USB FX2 microcontroller
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- Spartan-6 FPGA
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- SRAM memory chip
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- Pin headers for various JTAG pin assignments
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To compile the firmware, the SDCC compiler package is required. Most Linux
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distributions include SDCC in their official package repositories. The SDCC
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source code can be found at http://sdcc.sourceforge.net/
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Simply type "make bin" in the ANGIE directory to compile the firmware.
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"make clean" will remove all generated files except the BIN file
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required for downloading the firmware to ANGIE.
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Note that the EZ-USB FX2 microcontroller does not have on-chip flash,
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ANGIE include on-board EEPROM memory to store the firmware program of
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the FX2, but we are not going to use this method.
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Instead, upon initial connection of the ANGIE adapter to the host PC
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via USB, the EZ-USB FX2 core has enough intelligence to act as a
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stand-alone USB device, responding to USB control requests and allowing
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firmware download via a special VENDOR-type control request. Then, the
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EZ-USB microcontroller simulates a disconnect and re-connect to the USB bus.
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It may take up to two seconds for the host to recognize the newly connected
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device before OpenOCD can proceed to execute JTAG commands. This delay is
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only visible when OpenOCD first uses a blank (unconfigured) ANGIE device.
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Once the firmware downloaded, the FX2 microcontroller activate its GPIF mode,
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download the Spartan-6 FPGA's bitstream, program the FPGA rapidly, and switch
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back to default io mode.
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Once the user disconnects the ANGIE adapter, all its memory contents are lost
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and the firmware & bitstream download process has to be executed again.
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