ISD94100 Series Technical Reference Manual
Sep 9, 2019
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on the average frequency difference in 4 clocks of reference clock.
[3:2]
Reserved
Reserved. Any values read should be ignored. When writing to this field always write with
reset value.
[1:0]
FREQSEL
Trim Frequency Selection
This field indicates the target frequency of 48 MHz and 49.152 MHz internal high speed RC
oscillator (HIRC) auto trim.
During auto trim operation, if clock error detected with CESTOPEN is set to 1 or trim retry
limitation count reached, this field will be cleared to 00 automatically.
01 = Enable HIRC auto trim function and trim HIRC to 48 MHz.
11 = Enable HIRC auto trim function and trim HIRC to 49.152 MHz.
Others = Disable HIRC auto trim function.