AT32F425
Series Reference Manual
2022.03.30
Page 419
Ver 2.01
CRM_HICKCAL: the HICKCAL bit in the CRM module. This signal is used to calibrate the HICK
in bypass mode. The value is defined by the HICKCAL[7: 0] in the CRM_CTRL register.
CRM_HICKTRIM: the HICKTRIM bit in the CRM module. This signal is used to calibrate the
HICK in bypass mode. The value is defined by the HICKTRIM[5: 0] in the CRM_CTRL register.
The default value of the HICk is 32, which can be calibrated to 8MHz
±
0.25%. The HICK frequency
can be adjusted by 20kHz (design value) each time when the CRM_HICKTRIM value changes. In
other words, the HICK output frequency will increase by 20kHz eac time the CRM_HICKTRIM value
is decremented by one; the HICK output frequency will reduce by 20kHz each time the
CRM_HICKTRIM value is decremented by one.
USB_SOF: USB Start-of-Frame signal given by the USB device. Its high-level width is 12 system
clock cycles, a pulse signal of 1 ms.
HICKCLK: HICK clock. The original HICK output frequency is 48MHz, but the sampling clock
used by the HICK calibration module is frequency divider (1/6) clock, about 8MHz.
HICKCAL: HICK module calibration signal. For the HICK clock after frequency divion (1/6), the
HICK clock frequency will change by 40KHz (design value) each time the HICKCAL changes, which
is positively correlated. In other words, the HICK clock frequency will incease by 40KHz (design
value) eac time the HICKCAL is incremented by one; the HICK clock frequency will reduce by 40KHz
each time the HICKCAL is decremented by one.
HICKTRIM: HICK module calibration signal. For the HICK clock after frequency divion (1/6), the
HICK clock frequency will change by 20KHz (design value) each time the HICKCAL changes, which
is positively correlated.
Refer to
Section 21.6
for more information about the bit definition in the registers.
Figure 21-2 ACC block diagram
控制寄存器
(CTRL)
CALIBRATION
CONTROL
USB_SOF1
CRM_HICKCAL
RSLOST
CRM_HICKTRIM
HICKTRIM
HICKCAL
ACC_HICKTRIM
ACC_HICKCAL
C1
C2
C3
ACC
INTERRUPT
CONTROL
CALRDYIEN
EIEN
ENTRIM
HICKCLK
STEP
CALON
0
1
0
1
CALRDY
0
1
SOFSEL
USB_SOF2