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| author | Andreas Fritiofson <andreas.fritiofson@gmail.com> | 2017-01-03 00:18:34 +0100 |
|---|---|---|
| committer | Paul Fertser <fercerpav@gmail.com> | 2017-01-15 10:38:51 +0000 |
| commit | 52a396656aee2227fad8c9b54576ffec571e7e3e (patch) | |
| tree | 603ac1d8130848c127e96766ec4d662066ca98ba | |
| parent | 7436f7c2c0318fabce777d8886b302e3ca128606 (diff) | |
| download | riscv-openocd-52a396656aee2227fad8c9b54576ffec571e7e3e.zip riscv-openocd-52a396656aee2227fad8c9b54576ffec571e7e3e.tar.gz riscv-openocd-52a396656aee2227fad8c9b54576ffec571e7e3e.tar.bz2 | |
doc: Improve ftdi driver section
Fix typo and a sentence that sounds strange since the ft2232 driver
was removed.
Add documentation for the SWD signal usage.
Remove the text mentioning a default VID:PID which doesn't exist.
Change-Id: I27eba571f2f7c46bdb6ae623ab285595018e99d9
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: http://openocd.zylin.com/3935
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>
| -rw-r--r-- | doc/openocd.texi | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/doc/openocd.texi b/doc/openocd.texi index 8c10a26..5977c40 100644 --- a/doc/openocd.texi +++ b/doc/openocd.texi @@ -2408,11 +2408,10 @@ This driver is for adapters using the MPSSE (Multi-Protocol Synchronous Serial Engine) mode built into many FTDI chips, such as the FT2232, FT4232 and FT232H. The driver is using libusb-1.0 in asynchronous mode to talk to the FTDI device, -bypassing intermediate libraries like libftdi of D2XX. +bypassing intermediate libraries like libftdi or D2XX. -A major improvement of this driver is that support for new FTDI based adapters -can be added competely through configuration files, without the need to patch -and rebuild OpenOCD. +Support for new FTDI based adapters can be added competely through +configuration files, without the need to patch and rebuild OpenOCD. The driver uses a signal abstraction to enable Tcl configuration files to define outputs for one or several FTDI GPIO. These outputs can then be @@ -2421,6 +2420,12 @@ are reserved for nTRST, nSRST and LED (for blink) so that they, if defined, will be used for their customary purpose. Inputs can be read using the @command{ftdi_get_signal} command. +To support SWD, a signal named SWD_EN must be defined. It is set to 1 when the +SWD protocol is selected. When set, the adapter should route the SWDIO pin to +the data input. An SWDIO_OE signal, if defined, will be set to 1 or 0 as +required by the protocol, to tell the adapter to drive the data output onto +the SWDIO pin or keep the SWDIO pin Hi-Z, respectively. + Depending on the type of buffer attached to the FTDI GPIO, the outputs have to be controlled differently. In order to support tristateable signals such as nSRST, both a data GPIO and an output-enable GPIO can be specified for each @@ -2439,9 +2444,8 @@ These interfaces have several commands, used to configure the driver before initializing the JTAG scan chain: @deffn {Config Command} {ftdi_vid_pid} [vid pid]+ -The vendor ID and product ID of the adapter. If not specified, the FTDI -default values are used. -Currently, up to eight [@var{vid}, @var{pid}] pairs may be given, e.g. +The vendor ID and product ID of the adapter. Up to eight +[@var{vid}, @var{pid}] pairs may be given, e.g. @example ftdi_vid_pid 0x0403 0xcff8 0x15ba 0x0003 @end example |