Cypress FM4 Series - Procedure for Setting VBAT I;O Port

CHAPTER 7-2: VBAT Domain(A)
FM4 Peripheral Manual, Doc. No. 002-04856 Rev. *E 279
6. Procedure for Setting VBAT I/O Port
 When using VBAT I/O as a general-purpose I/O input
・Setting procedure example
The following is a setting example of using P46, P47, P48 and P49 all as general-purpose I/O inputs.
(1) Initiate the VBAT domain (see Figure 2-6).
(2) Set the general-purpose IO port to use it as the GPIO pin.
(3) Set the pull-up.
(4) Set the port output direction to the input direction.
(5) Transfer the setting value to the VBAT domain.
(6) Wait until the transfer is completed.
(1) Initialized VBAT Domain
(3) Write "00_0000" to VBPFR[5:0]
(4) Write "0000" to VBDDR[3:0]
(5) Write "Data" to VBPCR[3:0]
(6) Write "1" to WTCR20[5]
END
(2) WTCR10[7] == 0
Yes
No
(7) WTCR10[7] == 0
Yes
No