riscv-openocd/contrib/firmware/angie/c
Ahmed BOUDJELIDA da6c0e45a2 contrib/firmware: Add direction control for 'SCL' i2c signal
We want to keep the tri-state buffers located between the FPGA
and the board, in 'Z' state until we launch an i2c connection.

We launch an i2c start condition, make the SCL
direction 'OUT' to start the i2c protocol and at the end
of the i2c connection at the stop condition, we re-make
the tri-state buffers at 'Z' state.

Change-Id: Ic597a70d0427832547f6b539864c24ce20a18c64
Signed-off-by: Ahmed BOUDJELIDA <aboudjelida@nanoxplore.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7989
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
2024-01-29 13:36:27 +03:00
..
include contrib/firmware: Add direction control for 'SCL' i2c signal 2024-01-29 13:36:27 +03:00
src contrib/firmware: Add direction control for 'SCL' i2c signal 2024-01-29 13:36:27 +03:00
Makefile contrib/firmware: add new i2c bit-banging feature to angie's firmware 2023-08-26 11:45:43 +00:00
README contrib/firmware: add new i2c bit-banging feature to angie's firmware 2023-08-26 11:45:43 +00:00

README

#SPDX-License-Identifier: GPL-2.0-or-later

This is the ANGIE firmware for ANGIE USB-JTAG adapter.

The main components of ANGIE adapter are:
- Cypress EZ-USB FX2 microcontroller
- Spartan-6 FPGA
- SRAM memory chip
- Pin headers for various JTAG pin assignments

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 bin" in the ANGIE directory to compile the firmware.
"make clean" will remove all generated files except the BIN file
required for downloading the firmware to ANGIE.

Note that the EZ-USB FX2 microcontroller does not have on-chip flash,
ANGIE include on-board EEPROM memory to store the firmware program of
the FX2, but we are not going to use this method.

Instead, upon initial connection of the ANGIE adapter to the host PC
via USB, the EZ-USB FX2 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) ANGIE device.

Once the firmware downloaded, the FX2 microcontroller activate its GPIF mode,
download the Spartan-6 FPGA's bitstream, program the FPGA rapidly, and switch
back to default io mode.

Once the user disconnects the ANGIE adapter, all its memory contents are lost
and the firmware & bitstream download process has to be executed again.