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1256E User Manual
Racal Instruments © 2002
the top line reads:
>---STORE/RECALL---<
2.
Select line 2 (next to the top line) by pressing the second
key. Rotate the knob until line 2 of the display reads as
follows:
---STORE/RECALL---
>
Type: State
Config: Defaults
Action: <select>
3.
Press the third key to select line 3 of the display (option).
Rotate the knob until line 3 reads:
---STORE/RECALL---
Type: State
> Config: Powerup
Action: <select>
4.
Press the fourth key to select line 4 of the display. Rotate
the knob until line 4 reads:
---STORE/RECALL---
Type: State
> Config: Powerup
<
Do?: Store
Press the fourth key (bottom) to store the power-up state.
Pressing any other key cancels the change.
After storing the switch state, the non-volatile image
must be written to non-volatile RAM. Refer to the
section Updating Non-Volatile RAM for instructions.
Updating Non-Volatile RAM
Non-volatile (flash) RAM is inherently slow. If presets were stored
directly in non-volatile RAM, the user would have to wait several
seconds for each store operation. This may not always be an
inconvenience when working with the front-panel controls, but
would certainly slow down software that automatically sets up
and stores many presets.
To avoid the delay after storing each preset, the presets are
written to a temporary area of the static random-access memory
(SRAM). This memory is volatile (will erase upon power-down),
but is very fast. This allows presets to be stored rapidly. Once the
last desired preset has been stored, the presets stored in SRAM
(known as the SRAM image) may be written to non-volatile RAM
all at once. Since the non-volatile RAM is block-oriented, it takes
the same amount of time to write many presets as to write just
one. Thus, by writing all of the desired presets to non-volatile
<
<
<
NOTE
Using the Front-Panel Controls 3-27
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