Cypress FM4 Series - Page 252

CHAPTER 7-2: VBAT Domain(A)
252 FM4 Peripheral Manual, Doc. No. 002-04856 Rev. *E
The difference between Type 2 Circuit and Type 3 Circuit is the clock for the recall operation and save
operation.
 Interface circuit type 4
Figure 2-5 Configuration of Interface Circuit Type 4
Use this circuit type if the register has to retain data even when the VCC power supply is off.
Table 2-5 Behavior of Register of Interface Circuit Type 4
Behavior of Register/Buffer
Initialization of register
Initialization of register by the power-on signal of the VBAT Domain
Bus read
Data in the buffer is read to the bus.
Bus write
Directly affects the operation of the VBAT domain.
Circuit Type 4 does not require a recall operation or save operation.
Always-on Domain
Internal bus
VBAT Domain
FF
(Register)
Peripheral
function
Level shifter
Isolator