Cypress FM4 Series - Page 291

CHAPTER 7-2: VBAT Domain(A)
FM4 Peripheral Manual, Doc. No. 002-04856 Rev. *E 291
VBPFR[5:2] setting combinations are as shown in Table 7-4.
Table 7-4 VBPFR[5:2] Setting Combinations.
VBPFR[5]
VBPFR[4]
VBPFR[3]
VBPFR[2]
GPIO
0
0
0
0
32kHz oscillation
0
1
-
-
GPIO
1
0
0
0
P46 external clock input
1
1
1
0
To use the 32 kHz oscillation circuit, set the function setting bit (VBPFR[5:4]) of the oscillation pin to 0b01.
This enables the 32 kHz oscillation circuit to be used without depending on VBPFR[3:2].
To use P46/X0A as an external clock, set VBPFR[5:2] to 0b1110, and then input an external clock from
P46/X0A. In this case, P47 can be used as the GPIO pin.