Svd3 Operations; Svd3 Interrupt And Reset; Svd3 Interrupt - Epson Arm S1C31 Series Technical Manual

11 SUPPLY VOLTAGE DETECTOR (SVD3)

11.4.2 SVD3 Operations

Continuous operation mode
SVD3 operates in continuous operation mode by default (SVD3CTL.SVDMD[1:0] bits = 0x0). In this mode,
SVD3 operates continuously while the SVD3CTL.MODEN bit is set to 1 and it keeps loading the detection
results to the SVD3INTF.SVDDT bit. During this period, the current detection results can be obtained by read-
ing the SVD3INTF.SVDDT bit as necessary. Furthermore, an interrupt (if the SVD3CTL.SVDRE[3:0] bits ≠
0xa) or a reset (if the SVD3CTL.SVDRE[3:0] bits = 0xa) can be generated when the SVD3INTF.SVDDT bit is
set to 1 (low power supply voltage is detected). This mode can keep detecting power supply voltage drop after
the voltage detection masking time has elapsed even if the IC is placed into SLEEP status or accidental clock
stoppage has occurred.
Intermittent operation mode
SVD3 operates in intermittent operation mode when the SVD3CTL.SVDMD[1:0] bits are set to 0x1 to 0x3. In
this mode, SVD3 turns on at an interval set using the SVD3CTL.SVDMD[1:0] bits to perform detection opera-
tion and then it turns off while the SVD3CTL.MODEN bit is set to 1. During this period, the latest detection
results can be obtained by reading the SVD3INTF.SVDDT bit as necessary. Furthermore, an interrupt or a reset
can be generated when SVD3 has successively detected low power supply voltage the number of times speci-
fied by the SVD3CTL.SVDSC[1:0] bits.
(1) When the SVD3CTL.SVDMD[1:0] bits = 0x0 (continuous operation mode)
SVD3CTL.MODEN
SVD3 operating status
SVD3INTF.SVDDT
Low power supply voltage
detection interrupt
(2) When the SVD3CTL.SVDMD[1:0] bits ≠ 0x0 (intermittent operation mode)
SVD3CTL.MODEN
SVD3 operating status
SVD3INTF.SVDDT
Low power supply voltage
detection interrupt

11.5 SVD3 Interrupt and Reset

11.5.1 SVD3 Interrupt

Setting the SVD3CTL.SVDRE[3:0] bits to a value other than 0xa allows use of the low power supply voltage de-
tection interrupt function.
Table 11.5.1.1 Low Power Supply Voltage Detection Interrupt Function
Interrupt Interrupt flag
Low power supply SVD3INTF.SVDIF
voltage detection
SVD3 provides the interrupt enable bit (SVD3INTE.SVDIE bit) corresponding to the interrupt flag (SVD3INTF.
SVDIF bit). An interrupt request is sent to the CPU only when the SVD3INTF.SVDIF bit is set while the interrupt
is enabled by the SVD3INTE.SVDIE bit. For more information on interrupt control, refer to the "Interrupt" chapter.
11-4
V
DD
V
DD
DET
V : Level set using the SVD3CTL.SVDC[4:0] bits
SVD
: Voltage detection masking time
DET
: Voltage detection operation
Figure 11.4.2.1 SVD3 Operations
In continuous operation mode
When the SVD3INTF.SVDDT bit is 1
In intermittent operation mode
When low power supply voltage is successively de-
tected the specified number of times
Seiko Epson Corporation
V
SVD
DET
V
SVD
DET
Set condition
S1C31D41 TECHNICAL MANUAL
V
SVD
V
SVD
Clear condition
Writing 1
(Rev. 1.1)