Cypress FM4 Series - Deep Standby Return Factor Register 1 (WRFSR)

CHAPTER 6: Low Power Consumption Mode
FM4 Peripheral Manual, Doc. No. 002-04856 Rev. *E 233
8.4 Deep Standby Return Factor Register 1 (WRFSR)
The Deep Standby Return Factor Register 1 indicates the return factors of the low voltage detection reset
and the INITX pin input reset that have occurred in a deep standby mode.
Bit
7
6
5
4
3
2
1
0
Field
Reserved
WLVDH
WINITX
Attribute
-
R
R
Initial value
000000
0
0
[bit7:2] Reserved: Reserved bits
These bits always read 0b000000.
Writing a value to these bits has no effect on operation.
[bit1] WLVHD: Low voltage detection reset return bit
This bit indicates the CPU has returned from a deep standby mode due to the low voltage detection reset.
Bit
Description
0
The CPU has not returned from a deep standby mode due to the low voltage detection reset. [initial
value]
1
The CPU has returned from a deep standby mode due to the low voltage detection reset.
[bit0] WINITX: INITX pin input reset return bit
This bit indicates the CPU has returned from a deep standby mode due to the INITX pin input reset.
Bit
Description
0
The CPU has not returned from a deep standby mode due to the INITX pin input reset. [initial value]
1
The CPU has returned from a deep standby mode due to the INITX pin input reset.
Notes:
− This register is initialized by the power-on reset and the low voltage detection reset. It is not
initialized by any reset other than the two mentioned before. In addition, reading this register
clears all its bits.
− This register can be set only in a deep standby mode.
− Please be sure to check that the return factor has not been set before making a transition to deep
standby mode. If the factor is set, please clear.