Theory of Operation
2715 Spectrum Analyzer Service Manual 3-41
HProvides for the ability to placeup to two markers on a displayed waveform
HImplement and display a B,C-- SaveA waveform
HDisplay readout information on thescreen
HProvide up to 28 Kbytes of nonvolatile storage area
HProvide two differentwaveform acquisition modes: Max Peak and Min/Max
HProvide a Max Hold function
The following sections s how the bit maps for each of the control regis ters on the
Display Storage board.
Mode Control Register 1. Mode Control R egister 1 is located in I/O space, at
location 0x0FA00. Mode Control Register 1 is a read/write register.Table 3--2
describes the Mode Control Register.
Table3 -2: Mode Control Register 1
Bit
Number Mnemonic
Activity
Level Description
7DSON_L Low Display Storage On
6DISP--A_L Low EnablesB,C --SaveA Display
5MAXHLD_L Low Enables m ax hold function
4PEAKDIS_L Low Enables m ax peak function
3HLF/FLL_L High Selects location of B, C--SaveA display
2ACQ_ON High Enables the acquisition system
1RDZEN High Not used
0DS_PROTECT High Not used
DSON_L. Enables the Display Storage board to display thedigitized waveforms
when low. Whenthis signal is high, the analog trace is drawn on the CRT.
DISP--A_L. Invokes the B,C--SaveA display on the CRT when low.
MAXHLD_L. Invokes the Max Hold algorithm for A andB waveforms when
low. In this mode agiven bin will only be updated when the new vertical data is
greater than the stored vertical data.
Control System Interface