tmp88f846ug TOSHIBA Semiconductor CORPORATION, tmp88f846ug Datasheet - Page 64

• Manufacturer Part Number: tmp88f846ug
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

7.4 Setting of register
7. Voltage detection circuit (VLTD)
7.4 Setting of register
Detection voltage level
7.3.4 Voltage detection flag and voltage detection status flag
7.4.1 Setting Procedure for Generate an interrupt
VDCR2<VD1EN>
VDCR1<VD1SF>
VDCR1<VD1F>
Figure 7-3 Change of voltage detection flag and voltage detection status flag
VDD level
relation between the supply voltage (VDD) and the threshold voltage (VD1LVL), i.e, whether VDD is above or
equal to VD1LVL or VDD is below VD1LVL.
causes the VDCR1<VD1F> flag to be set. This flag remains set until it is cleared by software.
VDCR1<VD1F> can only be cleared by writing a 0.
also causes the VDCR1<VD1SF> flag to be set to 1. When VDD rises above VD1LVL, the VDCR1<VD1SF>
flag is cleared to 0.
according to the relation between VDD and VD1LVL.
cycle before the voltage detect flag (VDCR1<VD1F>) is set.
voltage condition.
The voltage detect flag (VDCR1<VD1F>) and voltage detect status flag (VDCR1<VD1SF>) indicate the
When VDCR2<VD1EN>=1, a drop of the supply voltage (VDD) below the threshold voltage (VD1LVL)
Once VDCR1<VD1F> has been set to 1, this state is retained even if VDCR2<VD1EN> is cleared to 0.
When VDCR2<VD1EN>=1, a drop of the supply voltage (VDD) below the threshold voltage (VD1LVL)
Unlike the VDCR1<VD1F> flag, the VDCR1<VD1SF> flag does not remain set and changes its state
Note:) Depending on the voltage detect timing, the voltage detect status flag (VDCR1<VD1SF>) may be set one machine
The following shows the setting procedure for generating an INTVLTD interrupt upon detection of a low-
1. Clear the INTVLTD interrupt enable flag <EF4> to 0.
2. Select the threshold voltage by programming the VDCR1<VD1LVL> bits.
3. Clear the VDCR2<VD1MOD> bit to 0 to generate an INTVLTD interrupt upon detection of a low-
4. Set the VDCR2<VD1EN> bit to 1 to enable voltage detect operation.
5. Wait for 5 us until the voltage detecting circuit stabilizes.
6. Ensure that the VDCR1<VD1SF> is 0.
7. Clear the INTVLTD interrupt latch <IL4> to 0 and set the interrupt enable flag <EF4> to 1 to enable
voltage condition.
interrupts.
erated frequently. After returning from the low-voltage detect interrupt routine, insert wait processing as appropriate with con-
sideration given to transitions in the system supply voltage before clearing the interrupt latch
Note) If the selected threshold voltage (VD1LVL) is close to the supply voltage (VDD), INTVLTD interrupts may be gen-
VDCR2 because of "0" the flag is not set
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"0" the entry to VDCR1
.
TMP88F846UG