VICOR PI33 EVAL1 Series, Руководство пользователя

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UG:309 Page 10
Configuration Programming
The PI33xx‑xx has three programming registers that can be changed by the user as a one‑time change
only. Of each register, any bit that is not set may be set. The programming requires burning internal fuse
links as permanent memory. Once they are burned there is no way to change or reset the settings back
to default. For this reason, it is critical to be sure the settings are correct prior to clicking on the
burn button . The three registers are ENA_POL, SYN[3:0] and KBIT2. ENA_POL is programmed by using
the “ENA POL” soft key and dialog box. SYN[3:0] is programmed by the “SYNC” soft key and dialog
box. KBIT2 is programmed using the “KILL BIT2” soft key and dialog box.
The programmable values for the SYN[3:0] register are shown in Table 6. Bits 0 through 2 define the
delay setting between a synchronizing signal (rising or falling edge as selected) applied to the SYNCI
input and the SYNCO output rising edge, applied as a fraction of the main system clock period (MP).
The most significant bit SYN[3] determines which edge trigger occurs. A “1” indicates rising edge and a
“0” indicates falling edge. As an example, if the MP value is 1µs, and the SYNC dialog box reads “1101”,
the programmed delay is 500ns from the rising edge of the SYNCI input. The actual programmed value
does not take effect until the bits are actually burned so there is no way to measure the delay without
actually burning the value in. For this reason, the user should review the waveform plots in
Figures 12 – 19 to understand the timing relationship prior to attempting to burn the values into the
register. The value of main system clock can be found in the PI33xx‑xx data sheet for each part number.
Figure 10
Buck GUI capture of
common faults with
corresponding I
2
C™ Data
Figure 11
I
2
C bus capture