User's Manual Part 2

Host Computer Commands
RVP8 User’s Manual
May 2003
6–33
6.11 Reset (RESET)
The RESET command permits resetting either the entire RVP8 processor, or selected portions
thereof. Flags within the command word determine the action to be taken.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
| | | | | | | | | | | | | | | | |
| |Nv |Nse|Fif|Nv |Nv | 0 1 1 0 0 | Command
|_______________________|___|___|___|___|___|___________________|
Nv Reloads configuration from the saved nonvolatile settings. For compatibility with
RPV6 and RVP7, any of 3 bits will trigger this response.
Nse Reset the receiver noise levels to the power-up default value for all pulsewidths as
defined in the Mt setup questions (See Section 3.3.5).
Fif Remove any data currently in the output FIFO’s. This permits flushing output
data that was left from a previous command, so that new output can be read from
scratch. See notes in the Introduction to this chapter concerning actions taken by
the RVP8 when the output FIFO becomes full.
6.12 Define Trigger Generator Output Waveforms (TRIGWF)
Note: This opcode is obsolete, and is included only for backward compatibility
with the RVP6. The opcode is disabled by default (See Section 3.3.1), because
the interactive trigger setup procedure described in Section 4.4 is the preferred
method of defining all RVP8 triggers and timing. TRIGWF should not be used
in any new code applications that drive the RVP8.
The RVP8 has a built-in trigger generator that can synthesize six independent digital output
waveforms, each having arbitrary shape and being active anywhere in a window centered around
zero-range. The six trigger outputs can be defined by a 2048-word by 6-bit table which is
loaded from the user computer. The patterns are automatically read from the table and output to
the six trigger lines during each radar pulse. The six outputs can be used for transmitter triggers,
scope triggers, range strobes, PLL gates, etc. The writable waveform table makes the RVP8
unique, in that the detailed timing of trigger and related control signals can be easily adjusted in
software, without having to resort to reprogramming PROMs. This makes it possible for user
software to edit the trigger timing in a convenient interactive manner.
Trigger waveforms are loaded using the TRIGWF command. Four bits in the command word
(PW0 through PW3) select which pulsewidths will receive the new waveforms. On power-up,
all four pulsewidths are initialized to user-selected waveforms.
The first word following the TRIGWF command specifies the transition point of the POLAR0
polarization control signal. This control signal is either held low or high for the cases of fixed
horizontal or vertical polarization, or it alternates from pulse to pulse for fast-switching
polarization measurements such as Zdr. The transition point is specified as a value between 0
and 2047, where 1024 represents range zero. These units are the same as the time units for the
waveforms which follow, i.e., a 2048-word array holding 6-bit trigger patterns. Bit 0 in each of
these words affects the TGEN0 digital output line, bit 1 affects TGEN1, etc. The bits are output
at a 7.195MHz rate, and the beginning of the 1024th array word (1025th word following the