David Brownell <david-b@pacbell.net>:
Doc (mostly) update for jtag_khz: - switch to @deffn syntax - add entry for "jtag_rclk" - move deprecated "jtag_speed" into collection of deprecated calls And for ft2232, don't be the only adapter to *log* an error if RTCK is requested; it's already reported properly, like any other nonfatal command parameter. "jtag_rclk" just works as expected, without any scarey messages. git-svn-id: svn://svn.berlios.de/openocd/trunk@1910 b42882b7-edfa-0310-969c-e2dbd0fdcd60
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@ -1493,53 +1493,58 @@ The OpenOCD default value is 2 and for some systems a value of 10 has proved use
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Currently, there are no options available for the ep93xx interface.
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@section JTAG Speed
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@itemize @bullet
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@item @b{jtag_khz} <@var{reset speed kHz}>
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@cindex jtag_khz
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@anchor{JTAG Speed}
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JTAG clock setup is part of system setup.
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It @emph{does not belong with interface setup} since any interface
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only knows a few of the constraints for the JTAG clock speed.
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Sometimes the JTAG speed is
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changed during the target initialization process: (1) slow at
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reset, (2) program the CPU clocks, (3) run fast.
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Both the "slow" and "fast" clock rates are functions of the
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oscillators used, the chip, the board design, and sometimes
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power management software that may be active.
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It is debatable if this command belongs here - or in a board
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configuration file. In fact, in some situations the JTAG speed is
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changed during the target initialisation process (i.e.: (1) slow at
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reset, (2) program the CPU clocks, (3) run fast)
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The speed used during reset can be adjusted using pre_reset
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and post_reset event handlers.
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@xref{Target Events}.
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Speed 0 (khz) selects RTCK method. A non-zero speed is in KHZ. Hence: 3000 is 3mhz.
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If your system supports adaptive clocking (RTCK), configuring
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JTAG to use that is probably the most robust approach.
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However, it introduces delays to synchronize clocks; so it
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may not be the fastest solution.
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Not all interfaces support ``rtck''. If the interface device can not
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support the rate asked for, or can not translate from kHz to
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jtag_speed, then an error is returned.
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@b{NOTE:} Script writers should consider using @command{jtag_rclk}
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instead of @command{jtag_khz}.
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Make sure the JTAG clock is no more than @math{1/6th CPU-Clock}. This is
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especially true for synthesized cores (-S). Also see RTCK.
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@deffn {Command} jtag_khz max_speed_kHz
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A non-zero speed is in KHZ. Hence: 3000 is 3mhz.
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JTAG interfaces usually support a limited number of
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speeds. The speed actually used won't be faster
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than the speed specified.
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@b{NOTE: Script writers} If the target chip requires/uses RTCK -
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please use the command: 'jtag_rclk FREQ'. This Tcl proc (in
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startup.tcl) attempts to enable RTCK, if that fails it falls back to
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the specified frequency.
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As a rule of thumb, if you specify a clock rate make
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sure the JTAG clock is no more than @math{1/6th CPU-Clock}.
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This is especially true for synthesized cores (ARMxxx-S).
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Speed 0 (khz) selects RTCK method.
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@xref{FAQ RTCK}.
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If your system uses RTCK, you won't need to change the
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JTAG clocking after setup.
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Not all interfaces, boards, or targets support ``rtck''.
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If the interface device can not
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support it, an error is returned when you try to use RTCK.
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@end deffn
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@defun jtag_rclk fallback_speed_kHz
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@cindex RTCK
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This Tcl proc (defined in startup.tcl) attempts to enable RTCK/RCLK.
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If that fails (maybe the interface, board, or target doesn't
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support it), falls back to the specified frequency.
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@example
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# Fall back to 3mhz if RCLK is not supported
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jtag_rclk 3000
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# Fall back to 3mhz if RTCK is not supported
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jtag_rclk 3000
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@end example
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@item @b{DEPRECATED} @b{jtag_speed} - please use jtag_khz above.
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@cindex jtag_speed
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@*Limit the maximum speed of the JTAG interface. Usually, a value of zero means maximum
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speed. The actual effect of this option depends on the JTAG interface used.
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The speed used during reset can be adjusted using setting jtag_speed during
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pre_reset and post_reset events.
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@itemize @minus
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@item wiggler: maximum speed / @var{number}
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@item ft2232: 6MHz / (@var{number}+1)
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@item amt jtagaccel: 8 / 2**@var{number}
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@item jlink: maximum speed in kHz (0-12000), 0 will use RTCK
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@item rlink: 24MHz / @var{number}, but only for certain values of @var{number}
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@comment end speed list.
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@end itemize
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@comment END command list
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@end itemize
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@end defun
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@node Reset Configuration
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@chapter Reset Configuration
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@ -3696,6 +3701,20 @@ and @option{target cortex_m3 little reset_halt 0}.
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@item @b{flash auto_erase}
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@cindex flash auto_erase
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@*use @option{flash write_image} command passing @option{erase} as the first parameter. @xref{flash write_image}.
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@item @b{jtag_speed} value
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@*@xref{JTAG Speed}.
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Usually, a value of zero means maximum
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speed. The actual effect of this option depends on the JTAG interface used.
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@itemize @minus
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@item wiggler: maximum speed / @var{number}
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@item ft2232: 6MHz / (@var{number}+1)
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@item amt jtagaccel: 8 / 2**@var{number}
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@item jlink: maximum speed in kHz (0-12000), 0 will use RTCK
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@item rlink: 24MHz / @var{number}, but only for certain values of @var{number}
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@comment end speed list.
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@end itemize
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@item @b{load_binary}
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@cindex load_binary
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@*use @option{load_image} command with same args. @xref{load_image}.
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@ -3724,6 +3743,7 @@ halt
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@cindex faq
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@enumerate
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@item @b{RTCK, also known as: Adaptive Clocking - What is it?}
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@anchor{FAQ RTCK}
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@cindex RTCK
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@cindex adaptive clocking
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@*
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@ -446,7 +446,7 @@ static int ft2232_khz(int khz, int* jtag_speed)
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{
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if (khz==0)
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{
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LOG_ERROR("RCLK not supported");
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LOG_DEBUG("RTCK not supported");
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return ERROR_FAIL;
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}
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@ -2315,9 +2315,10 @@ int jtag_register_commands(struct command_context_s *cmd_ctx)
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register_command(cmd_ctx, NULL, "interface", handle_interface_command,
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COMMAND_CONFIG, "try to configure interface");
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register_command(cmd_ctx, NULL, "jtag_speed", handle_jtag_speed_command,
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COMMAND_ANY, "set jtag speed (if supported)");
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COMMAND_ANY, "(DEPRECATED) set jtag speed (if supported)");
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register_command(cmd_ctx, NULL, "jtag_khz", handle_jtag_khz_command,
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COMMAND_ANY, "same as jtag_speed, except it takes maximum khz as arguments. 0 KHz = RTCK.");
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COMMAND_ANY, "set maximum jtag speed (if supported); "
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"parameter is maximum khz, or 0 for adaptive clocking (RTCK).");
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register_command(cmd_ctx, NULL, "jtag_device", handle_jtag_device_command,
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COMMAND_CONFIG, "jtag_device <ir_length> <ir_expected> <ir_mask>");
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register_command(cmd_ctx, NULL, "reset_config", handle_reset_config_command,
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